diff --git a/fluent-interface/etc/fluent-interface.urm.puml b/fluent-interface/etc/fluent-interface.urm.puml
new file mode 100644
index 000000000000..d343a478bff0
--- /dev/null
+++ b/fluent-interface/etc/fluent-interface.urm.puml
@@ -0,0 +1,72 @@
+@startuml
+package com.iluwatar.fluentinterface.fluentiterable.simple {
+  class SimpleFluentIterable<E> {
+    - iterable : Iterable<E>
+    + SimpleFluentIterable<E>(iterable : Iterable<E>)
+    + asList() : List<E>
+    + filter(predicate : Predicate<? super E>) : FluentIterable<E>
+    + first() : Optional<E>
+    + first(count : int) : FluentIterable<E>
+    + forEach(action : Consumer<? super E>)
+    + from(iterable : Iterable<E>) : FluentIterable<E> {static}
+    + fromCopyOf(iterable : Iterable<E>) : FluentIterable<E> {static}
+    + getRemainingElementsCount() : int
+    + iterator() : Iterator<E>
+    + last() : Optional<E>
+    + last(count : int) : FluentIterable<E>
+    + map(function : Function<? super E, T>) : FluentIterable<T>
+    + spliterator() : Spliterator<E>
+    + toList(iterator : Iterator<E>) : List<E> {static}
+  }
+}
+package com.iluwatar.fluentinterface.app {
+  class App {
+    - LOGGER : Logger {static}
+    + App()
+    + main(args : String[]) {static}
+    - negatives() : Predicate<? super Integer> {static}
+    - positives() : Predicate<? super Integer> {static}
+    - prettyPrint(delimiter : String, prefix : String, iterable : Iterable<E>) {static}
+    - prettyPrint(prefix : String, iterable : Iterable<E>) {static}
+    - transformToString() : Function<Integer, String> {static}
+  }
+}
+package com.iluwatar.fluentinterface.fluentiterable.lazy {
+  abstract class DecoratingIterator<E> {
+    # fromIterator : Iterator<E>
+    - next : E
+    + DecoratingIterator<E>(fromIterator : Iterator<E>)
+    + computeNext() : E {abstract}
+    + hasNext() : boolean
+    + next() : E
+  }
+  class LazyFluentIterable<E> {
+    - iterable : Iterable<E>
+    # LazyFluentIterable<E>()
+    + LazyFluentIterable<E>(iterable : Iterable<E>)
+    + asList() : List<E>
+    + filter(predicate : Predicate<? super E>) : FluentIterable<E>
+    + first() : Optional<E>
+    + first(count : int) : FluentIterable<E>
+    + from(iterable : Iterable<E>) : FluentIterable<E> {static}
+    + iterator() : Iterator<E>
+    + last() : Optional<E>
+    + last(count : int) : FluentIterable<E>
+    + map(function : Function<? super E, T>) : FluentIterable<T>
+  }
+}
+package com.iluwatar.fluentinterface.fluentiterable {
+  interface FluentIterable<E> {
+    + asList() : List<E> {abstract}
+    + copyToList(iterable : Iterable<E>) : List<E> {static}
+    + filter(Predicate<? super E>) : FluentIterable<E> {abstract}
+    + first() : Optional<E> {abstract}
+    + first(int) : FluentIterable<E> {abstract}
+    + last() : Optional<E> {abstract}
+    + last(int) : FluentIterable<E> {abstract}
+    + map(Function<? super E, T>) : FluentIterable<T> {abstract}
+  }
+}
+LazyFluentIterable ..|> FluentIterable 
+SimpleFluentIterable ..|> FluentIterable 
+@enduml
\ No newline at end of file
diff --git a/function-composition/etc/function-composition.urm.puml b/function-composition/etc/function-composition.urm.puml
new file mode 100644
index 000000000000..79b2a898fd12
--- /dev/null
+++ b/function-composition/etc/function-composition.urm.puml
@@ -0,0 +1,12 @@
+@startuml
+package com.iluwatar.function.composition {
+  class App {
+    + App()
+    + main(args : String[]) {static}
+  }
+  class FunctionComposer {
+    + FunctionComposer()
+    + composeFunctions(f1 : Function<Integer, Integer>, f2 : Function<Integer, Integer>) : Function<Integer, Integer> {static}
+  }
+}
+@enduml
\ No newline at end of file
diff --git a/hexagonal-architecture/etc/hexagonal-architecture.urm.puml b/hexagonal-architecture/etc/hexagonal-architecture.urm.puml
new file mode 100644
index 000000000000..f86e734747f3
--- /dev/null
+++ b/hexagonal-architecture/etc/hexagonal-architecture.urm.puml
@@ -0,0 +1,282 @@
+@startuml
+package com.iluwatar.hexagonal.sampledata {
+  class SampleData {
+    - PLAYERS : List<PlayerDetails> {static}
+    - RANDOM : SecureRandom {static}
+    + SampleData()
+    - getRandomPlayerDetails() : PlayerDetails {static}
+    + submitTickets(lotteryService : LotteryService, numTickets : int) {static}
+  }
+}
+package com.iluwatar.hexagonal.service {
+  class ConsoleLottery {
+    - LOGGER : Logger {static}
+    + ConsoleLottery()
+    + main(args : String[]) {static}
+    - printMainMenu() {static}
+    - readString(scanner : Scanner) : String {static}
+  }
+  interface LotteryConsoleService {
+    + addFundsToLotteryAccount(WireTransfers, Scanner) {abstract}
+    + checkTicket(LotteryService, Scanner) {abstract}
+    + queryLotteryAccountFunds(WireTransfers, Scanner) {abstract}
+    + submitTicket(LotteryService, Scanner) {abstract}
+  }
+  class LotteryConsoleServiceImpl {
+    - logger : Logger
+    + LotteryConsoleServiceImpl(logger : Logger)
+    + addFundsToLotteryAccount(bank : WireTransfers, scanner : Scanner)
+    + checkTicket(service : LotteryService, scanner : Scanner)
+    + queryLotteryAccountFunds(bank : WireTransfers, scanner : Scanner)
+    - readString(scanner : Scanner) : String
+    + submitTicket(service : LotteryService, scanner : Scanner)
+  }
+}
+package com.iluwatar.hexagonal.mongo {
+  class MongoConnectionPropertiesLoader {
+    - DEFAULT_HOST : String {static}
+    - DEFAULT_PORT : int {static}
+    - LOGGER : Logger {static}
+    + MongoConnectionPropertiesLoader()
+    + load() {static}
+  }
+}
+package com.iluwatar.hexagonal.domain {
+  class LotteryAdministration {
+    - notifications : LotteryEventLog
+    - repository : LotteryTicketRepository
+    - wireTransfers : WireTransfers
+    + LotteryAdministration(repository : LotteryTicketRepository, notifications : LotteryEventLog, wireTransfers : WireTransfers)
+    + getAllSubmittedTickets() : Map<LotteryTicketId, LotteryTicket>
+    + performLottery() : LotteryNumbers
+    + resetLottery()
+  }
+  class LotteryConstants {
+    + PLAYER_MAX_BALANCE : int {static}
+    + PRIZE_AMOUNT : int {static}
+    + SERVICE_BANK_ACCOUNT : String {static}
+    + SERVICE_BANK_ACCOUNT_BALANCE : int {static}
+    + TICKET_PRIZE : int {static}
+    - LotteryConstants()
+  }
+  class LotteryNumbers {
+    + MAX_NUMBER : int {static}
+    + MIN_NUMBER : int {static}
+    + NUM_NUMBERS : int {static}
+    - numbers : Set<Integer>
+    - LotteryNumbers()
+    - LotteryNumbers(givenNumbers : Set<Integer>)
+    # canEqual(other : Object) : boolean
+    + create(givenNumbers : Set<Integer>) : LotteryNumbers {static}
+    + createRandom() : LotteryNumbers {static}
+    + equals(o : Object) : boolean
+    - generateRandomNumbers()
+    + getNumbers() : Set<Integer>
+    + getNumbersAsString() : String
+    + hashCode() : int
+    + toString() : String
+  }
+  -class RandomNumberGenerator {
+    - randomIterator : OfInt
+    + RandomNumberGenerator(min : int, max : int)
+    + nextInt() : int
+  }
+  class LotteryService {
+    - notifications : LotteryEventLog
+    - repository : LotteryTicketRepository
+    - wireTransfers : WireTransfers
+    + LotteryService(repository : LotteryTicketRepository, notifications : LotteryEventLog, wireTransfers : WireTransfers)
+    + checkTicketForPrize(id : LotteryTicketId, winningNumbers : LotteryNumbers) : LotteryTicketCheckResult
+    + submitTicket(ticket : LotteryTicket) : Optional<LotteryTicketId>
+  }
+  class LotteryTicketCheckResult {
+    - prizeAmount : int
+    - result : CheckResult
+    + LotteryTicketCheckResult(result : CheckResult)
+    + LotteryTicketCheckResult(result : CheckResult, prizeAmount : int)
+    # canEqual(other : Object) : boolean
+    + equals(o : Object) : boolean
+    + getPrizeAmount() : int
+    + getResult() : CheckResult
+    + hashCode() : int
+  }
+  enum CheckResult {
+    + NO_PRIZE {static}
+    + TICKET_NOT_SUBMITTED {static}
+    + WIN_PRIZE {static}
+    + valueOf(name : String) : CheckResult {static}
+    + values() : CheckResult[] {static}
+  }
+  class LotteryTicketId {
+    - id : int
+    - numAllocated : AtomicInteger {static}
+    + LotteryTicketId()
+    + LotteryTicketId(id : int)
+    # canEqual(other : Object) : boolean
+    + equals(o : Object) : boolean
+    + getId() : int
+    + hashCode() : int
+    + toString() : String
+  }
+  class LotteryUtils {
+    - LotteryUtils()
+    + checkTicketForPrize(repository : LotteryTicketRepository, id : LotteryTicketId, winningNumbers : LotteryNumbers) : LotteryTicketCheckResult {static}
+  }
+}
+package com.iluwatar.hexagonal.banking {
+  class InMemoryBank {
+    - accounts : Map<String, Integer> {static}
+    + InMemoryBank()
+    + getFunds(bankAccount : String) : int
+    + setFunds(bankAccount : String, amount : int)
+    + transferFunds(amount : int, sourceAccount : String, destinationAccount : String) : boolean
+  }
+  class MongoBank {
+    - DEFAULT_ACCOUNTS_COLLECTION : String {static}
+    - DEFAULT_DB : String {static}
+    - accountsCollection : MongoCollection<Document>
+    - database : MongoDatabase
+    - mongoClient : MongoClient
+    + MongoBank()
+    + MongoBank(dbName : String, accountsCollectionName : String)
+    + connect()
+    + connect(dbName : String, accountsCollectionName : String)
+    + getAccountsCollection() : MongoCollection<Document>
+    + getDatabase() : MongoDatabase
+    + getFunds(bankAccount : String) : int
+    + getMongoClient() : MongoClient
+    + setFunds(bankAccount : String, amount : int)
+    + transferFunds(amount : int, sourceAccount : String, destinationAccount : String) : boolean
+  }
+  interface WireTransfers {
+    + getFunds(String) : int {abstract}
+    + setFunds(String, int) {abstract}
+    + transferFunds(int, String, String) : boolean {abstract}
+  }
+}
+package com.iluwatar.hexagonal.database {
+  class InMemoryTicketRepository {
+    - tickets : Map<LotteryTicketId, LotteryTicket> {static}
+    + InMemoryTicketRepository()
+    + deleteAll()
+    + findAll() : Map<LotteryTicketId, LotteryTicket>
+    + findById(id : LotteryTicketId) : Optional<LotteryTicket>
+    + save(ticket : LotteryTicket) : Optional<LotteryTicketId>
+  }
+  interface LotteryTicketRepository {
+    + deleteAll() {abstract}
+    + findAll() : Map<LotteryTicketId, LotteryTicket> {abstract}
+    + findById(LotteryTicketId) : Optional<LotteryTicket> {abstract}
+    + save(LotteryTicket) : Optional<LotteryTicketId> {abstract}
+  }
+  class MongoTicketRepository {
+    - DEFAULT_COUNTERS_COLLECTION : String {static}
+    - DEFAULT_DB : String {static}
+    - DEFAULT_TICKETS_COLLECTION : String {static}
+    - TICKET_ID : String {static}
+    - countersCollection : MongoCollection<Document>
+    - database : MongoDatabase
+    - mongoClient : MongoClient
+    - ticketsCollection : MongoCollection<Document>
+    + MongoTicketRepository()
+    + MongoTicketRepository(dbName : String, ticketsCollectionName : String, countersCollectionName : String)
+    + connect()
+    + connect(dbName : String, ticketsCollectionName : String, countersCollectionName : String)
+    + deleteAll()
+    - docToTicket(doc : Document) : LotteryTicket
+    + findAll() : Map<LotteryTicketId, LotteryTicket>
+    + findById(id : LotteryTicketId) : Optional<LotteryTicket>
+    + getCountersCollection() : MongoCollection<Document>
+    + getNextId() : int
+    + getTicketsCollection() : MongoCollection<Document>
+    - initCounters()
+    + save(ticket : LotteryTicket) : Optional<LotteryTicketId>
+  }
+}
+package com.iluwatar.hexagonal {
+  class App {
+    + App()
+    + main(args : String[]) {static}
+  }
+}
+package com.iluwatar.hexagonal.administration {
+  class ConsoleAdministration {
+    - LOGGER : Logger {static}
+    + ConsoleAdministration()
+    + main(args : String[]) {static}
+    - printMainMenu() {static}
+    - readString(scanner : Scanner) : String {static}
+  }
+  interface ConsoleAdministrationSrv {
+    + getAllSubmittedTickets() {abstract}
+    + performLottery() {abstract}
+    + resetLottery() {abstract}
+  }
+  class ConsoleAdministrationSrvImpl {
+    - administration : LotteryAdministration
+    - logger : Logger
+    + ConsoleAdministrationSrvImpl(administration : LotteryAdministration, logger : Logger)
+    + getAllSubmittedTickets()
+    + performLottery()
+    + resetLottery()
+  }
+}
+package com.iluwatar.hexagonal.eventlog {
+  interface LotteryEventLog {
+    + prizeError(PlayerDetails, int) {abstract}
+    + ticketDidNotWin(PlayerDetails) {abstract}
+    + ticketSubmitError(PlayerDetails) {abstract}
+    + ticketSubmitted(PlayerDetails) {abstract}
+    + ticketWon(PlayerDetails, int) {abstract}
+  }
+  class MongoEventLog {
+    - DEFAULT_DB : String {static}
+    - DEFAULT_EVENTS_COLLECTION : String {static}
+    - EMAIL : String {static}
+    + MESSAGE : String {static}
+    - PHONE : String {static}
+    - database : MongoDatabase
+    - eventsCollection : MongoCollection<Document>
+    - mongoClient : MongoClient
+    - stdOutEventLog : StdOutEventLog
+    + MongoEventLog()
+    + MongoEventLog(dbName : String, eventsCollectionName : String)
+    + connect()
+    + connect(dbName : String, eventsCollectionName : String)
+    + getDatabase() : MongoDatabase
+    + getEventsCollection() : MongoCollection<Document>
+    + getMongoClient() : MongoClient
+    + prizeError(details : PlayerDetails, prizeAmount : int)
+    + ticketDidNotWin(details : PlayerDetails)
+    + ticketSubmitError(details : PlayerDetails)
+    + ticketSubmitted(details : PlayerDetails)
+    + ticketWon(details : PlayerDetails, prizeAmount : int)
+  }
+  class StdOutEventLog {
+    - LOGGER : Logger {static}
+    + StdOutEventLog()
+    + prizeError(details : PlayerDetails, prizeAmount : int)
+    + ticketDidNotWin(details : PlayerDetails)
+    + ticketSubmitError(details : PlayerDetails)
+    + ticketSubmitted(details : PlayerDetails)
+    + ticketWon(details : PlayerDetails, prizeAmount : int)
+  }
+}
+LotteryAdministration -->  "-wireTransfers" WireTransfers
+LotteryService -->  "-notifications" LotteryEventLog
+LotteryAdministration -->  "-repository" LotteryTicketRepository
+MongoEventLog -->  "-stdOutEventLog" StdOutEventLog
+LotteryService -->  "-wireTransfers" WireTransfers
+LotteryAdministration -->  "-notifications" LotteryEventLog
+ConsoleAdministrationSrvImpl -->  "-administration" LotteryAdministration
+LotteryService -->  "-repository" LotteryTicketRepository
+LotteryTicketCheckResult -->  "-result" CheckResult
+ConsoleAdministrationSrvImpl ..|> ConsoleAdministrationSrv 
+InMemoryBank ..|> WireTransfers 
+MongoBank ..|> WireTransfers 
+InMemoryTicketRepository ..|> LotteryTicketRepository 
+MongoTicketRepository ..|> LotteryTicketRepository 
+MongoEventLog ..|> LotteryEventLog 
+StdOutEventLog ..|> LotteryEventLog 
+LotteryConsoleServiceImpl ..|> LotteryConsoleService 
+@enduml
\ No newline at end of file
diff --git a/localization/ir/README.md b/localization/ir/README.md
new file mode 100644
index 000000000000..507a4c53298a
--- /dev/null
+++ b/localization/ir/README.md
@@ -0,0 +1,59 @@
+<!-- the line below needs to be an empty line C: (its because kramdown isnt
+     that smart and dearly wants an empty line before a heading to be able to
+     display it as such, e.g. website) -->
+
+# الگوهای طراحی پیاده‌سازی شده در جاوا
+
+![Java CI](https://github.com/iluwatar/java-design-patterns/workflows/Java%20CI/badge.svg)
+[![License MIT](https://img.shields.io/badge/license-MIT-blue.svg)](https://raw.githubusercontent.com/iluwatar/java-design-patterns/master/LICENSE.md)
+[![Lines of Code](https://sonarcloud.io/api/project_badges/measure?project=iluwatar_java-design-patterns&metric=ncloc)](https://sonarcloud.io/dashboard?id=iluwatar_java-design-patterns)
+[![Coverage](https://sonarcloud.io/api/project_badges/measure?project=iluwatar_java-design-patterns&metric=coverage)](https://sonarcloud.io/dashboard?id=iluwatar_java-design-patterns)
+[![Join the chat at https://gitter.im/iluwatar/java-design-patterns](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/iluwatar/java-design-patterns?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+<!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
+[![All Contributors](https://img.shields.io/badge/all_contributors-167-orange.svg?style=flat-square)](#contributors-)
+<!-- ALL-CONTRIBUTORS-BADGE:END -->
+
+<br/>
+
+خواندن به زبان های مختلف: [**zh**](localization/zh/README.md), [**ko**](localization/ko/README.md), [**fr**](localization/fr/README.md), [**tr**](localization/tr/README.md), [**ar**](localization/ar/README.md), [**es**](localization/es/README.md), [**pt**](localization/pt/README.md), [**id**](localization/id/README.md), [**ru**](localization/ru/README.md), [**de**](localization/de/README.md), [**ja**](localization/ja/README.md), [**vi**](localization/vi/README.md), [**bn**](localization/bn/README.md), [**np**](localization/ne/README.md), [**it**](localization/it/README.md), [**da**](localization/da/README.md)
+<br/>
+
+# مقدمه
+
+الگوهای طراحی بهترین شیوه‌های رسمی‌شده‌ای هستند که یک برنامه‌نویس می‌تواند برای حل مشکلات رایج در طراحی یک برنامه یا سیستم استفاده کند.
+
+الگوهای طراحی می‌توانند فرآیند توسعه را با ارائه پارادایم‌های توسعه اثبات‌شده و آزمایش‌شده تسریع کنند.
+
+استفاده مجدد از الگوهای طراحی به جلوگیری از مشکلات جزئی که باعث خطاهای بزرگ می‌شوند کمک می‌کند و همچنین خوانایی کد را برای توسعه‌دهندگان و معمارانی که با این الگوها آشنا هستند بهبود می‌بخشد.
+
+
+# شروع
+
+این سایت الگوهای طراحی در جاوا را ارائه می‌دهد. راه‌حل‌ها توسط برنامه‌نویسان و معماران باتجربه از جامعه متن‌باز توسعه داده شده‌اند. الگوها را می‌توان از طریق توضیحات سطح بالا یا با مشاهده کد منبع آن‌ها جستجو کرد. نمونه‌های کد منبع به خوبی توضیح داده شده‌اند و می‌توانند به عنوان آموزش‌های برنامه‌نویسی برای نحوه پیاده‌سازی یک الگوی خاص در نظر گرفته شوند. ما از محبوب‌ترین فناوری‌های متن‌باز جاوا استفاده می‌کنیم.
+
+
+قبل از غوطه‌ور شدن در مطالب، باید با مفاهیم زیر آشنا باشید
+[اصول طراحی نرم‌افزار](https://java-design-patterns.com/principles/).
+
+همه طراحی‌ها باید تا حد امکان ساده باشند. باید با اصول KISS و YAGNI شروع کنید و ساده‌ترین راه‌حلی را که کار می‌کند انتخاب کنید. پیچیدگی و الگوها فقط زمانی باید معرفی شوند که برای گسترش عملی لازم باشند.
+
+
+هنگامی که با این مفاهیم آشنا شدید، می‌توانید با مطالب عمیق‌تر شروع کنید
+[الگوهای طراحی موجود](https://java-design-patterns.com/patterns/)
+با استفاده از هر یک از رویکردهای زیر
+
+ - جستجوی یک الگوی خاص با نام آن. نمی‌توانید یکی را پیدا کنید؟ یک الگوی جدید گزارش دهید [aکوی](https://github.com/iluwatar/java-design-patterns/issues).
+ - با استفاده از برچسب‌هایی مانند `Performance`, `Gang of Four` یا `Data access`.
+ - با استفاده از دسته‌بندی‌های الگوها, `Creational`, `Behavioral` و دیگر.
+
+امیدواریم که راه حل های مبتنی بر شیء ارائه شده در این سایت برای شما در معماری ها مفید باشد و همانند ما در توسعه آنها لذت ببرید.
+
+# چگونه مشارکت کنیم
+
+اگر مایل به مشارکت در پروژه هستید، اطلاعات مربوطه را در بخش [ویکی توسعه‌دهنده](https://github.com/iluwatar/java-design-patterns/wiki). 
+ما به شما کمک می‌کنیم و به سوالات شما در بخش [اتاق گفتگوی گیتر](https://gitter.im/iluwatar/java-design-patterns).
+
+# لیценس
+
+این پروژه بر اساس شرایط مجوز MIT مجوز داده شده است.
+
diff --git a/marker-interface/etc/marker-interface.urm.puml b/marker-interface/etc/marker-interface.urm.puml
new file mode 100644
index 000000000000..02af47ddf261
--- /dev/null
+++ b/marker-interface/etc/marker-interface.urm.puml
@@ -0,0 +1,2 @@
+@startuml
+@enduml
\ No newline at end of file
diff --git a/microservices-aggregrator/etc/microservices-aggregrator.urm.puml b/microservices-aggregrator/etc/microservices-aggregrator.urm.puml
new file mode 100644
index 000000000000..02af47ddf261
--- /dev/null
+++ b/microservices-aggregrator/etc/microservices-aggregrator.urm.puml
@@ -0,0 +1,2 @@
+@startuml
+@enduml
\ No newline at end of file
diff --git a/microservices-api-gateway/etc/microservices-api-gateway.urm.puml b/microservices-api-gateway/etc/microservices-api-gateway.urm.puml
new file mode 100644
index 000000000000..02af47ddf261
--- /dev/null
+++ b/microservices-api-gateway/etc/microservices-api-gateway.urm.puml
@@ -0,0 +1,2 @@
+@startuml
+@enduml
\ No newline at end of file
diff --git a/microservices-log-aggregation/etc/microservices-log-aggregation.urm.puml b/microservices-log-aggregation/etc/microservices-log-aggregation.urm.puml
new file mode 100644
index 000000000000..1d4551ed025f
--- /dev/null
+++ b/microservices-log-aggregation/etc/microservices-log-aggregation.urm.puml
@@ -0,0 +1,68 @@
+@startuml
+package com.iluwatar.logaggregation {
+  class App {
+    + App()
+    + main(args : String[]) {static}
+  }
+  class CentralLogStore {
+    - LOGGER : Logger {static}
+    - logs : ConcurrentLinkedQueue<LogEntry>
+    + CentralLogStore()
+    + displayLogs()
+    + storeLog(logEntry : LogEntry)
+  }
+  class LogAggregator {
+    - BUFFER_THRESHOLD : int {static}
+    - LOGGER : Logger {static}
+    - buffer : ConcurrentLinkedQueue<LogEntry>
+    - centralLogStore : CentralLogStore
+    - executorService : ExecutorService
+    - logCount : AtomicInteger
+    - minLogLevel : LogLevel
+    + LogAggregator(centralLogStore : CentralLogStore, minLogLevel : LogLevel)
+    + collectLog(logEntry : LogEntry)
+    - flushBuffer()
+    - startBufferFlusher()
+    + stop()
+  }
+  class LogEntry {
+    - level : LogLevel
+    - message : String
+    - serviceName : String
+    - timestamp : LocalDateTime
+    + LogEntry(serviceName : String, level : LogLevel, message : String, timestamp : LocalDateTime)
+    # canEqual(other : Object) : boolean
+    + equals(o : Object) : boolean
+    + getLevel() : LogLevel
+    + getMessage() : String
+    + getServiceName() : String
+    + getTimestamp() : LocalDateTime
+    + hashCode() : int
+    + setLevel(level : LogLevel)
+    + setMessage(message : String)
+    + setServiceName(serviceName : String)
+    + setTimestamp(timestamp : LocalDateTime)
+    + toString() : String
+  }
+  enum LogLevel {
+    + DEBUG {static}
+    + ERROR {static}
+    + INFO {static}
+    + valueOf(name : String) : LogLevel {static}
+    + values() : LogLevel[] {static}
+  }
+  class LogProducer {
+    - LOGGER : Logger {static}
+    - aggregator : LogAggregator
+    - serviceName : String
+    + LogProducer(serviceName : String, aggregator : LogAggregator)
+    + generateLog(level : LogLevel, message : String)
+  }
+}
+LogAggregator -->  "-centralLogStore" CentralLogStore
+LogEntry -->  "-level" LogLevel
+CentralLogStore -->  "-logs" LogEntry
+LogAggregator -->  "-buffer" LogEntry
+LogAggregator -->  "-minLogLevel" LogLevel
+LogProducer -->  "-aggregator" LogAggregator
+@enduml
\ No newline at end of file
diff --git a/queue-based-load-leveling/etc/queue-based-load-leveling.urm.puml b/queue-based-load-leveling/etc/queue-based-load-leveling.urm.puml
new file mode 100644
index 000000000000..ca90842d92dd
--- /dev/null
+++ b/queue-based-load-leveling/etc/queue-based-load-leveling.urm.puml
@@ -0,0 +1,44 @@
+@startuml
+package com.iluwatar.queue.load.leveling {
+  class App {
+    - LOGGER : Logger {static}
+    - SHUTDOWN_TIME : int {static}
+    + App()
+    + main(args : String[]) {static}
+  }
+  class Message {
+    - msg : String
+    + Message(msg : String)
+    + getMsg() : String
+    + toString() : String
+  }
+  class MessageQueue {
+    - LOGGER : Logger {static}
+    - blkQueue : BlockingQueue<Message>
+    + MessageQueue()
+    + retrieveMsg() : Message
+    + submitMsg(msg : Message)
+  }
+  class ServiceExecutor {
+    - LOGGER : Logger {static}
+    - msgQueue : MessageQueue
+    + ServiceExecutor(msgQueue : MessageQueue)
+    + run()
+  }
+  interface Task {
+    + submit(Message) {abstract}
+  }
+  class TaskGenerator {
+    - LOGGER : Logger {static}
+    - msgCount : int
+    - msgQueue : MessageQueue
+    + TaskGenerator(msgQueue : MessageQueue, msgCount : int)
+    + run()
+    + submit(msg : Message)
+  }
+}
+MessageQueue -->  "-blkQueue" Message
+ServiceExecutor -->  "-msgQueue" MessageQueue
+TaskGenerator -->  "-msgQueue" MessageQueue
+TaskGenerator ..|> Task 
+@enduml
\ No newline at end of file
diff --git a/update-header.sh b/update-header.sh
index 48da4dcd6125..568d00d52a03 100755
--- a/update-header.sh
+++ b/update-header.sh
@@ -1,4 +1,29 @@
 #!/bin/bash
+#
+# This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt).
+#
+# The MIT License
+# Copyright © 2014-2022 Ilkka Seppälä
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+#
+
 
 # Find all README.md files in subdirectories one level deep
 # and replace "### " with "## " at the beginning of lines
diff --git a/virtual-proxy/etc/virtual-proxy.urm.puml b/virtual-proxy/etc/virtual-proxy.urm.puml
new file mode 100644
index 000000000000..e30149e3809e
--- /dev/null
+++ b/virtual-proxy/etc/virtual-proxy.urm.puml
@@ -0,0 +1,26 @@
+@startuml
+package com.iluwatar.virtual.proxy {
+  class App {
+    + App()
+    + main(args : String[]) {static}
+  }
+  interface ExpensiveObject {
+    + process() {abstract}
+  }
+  class RealVideoObject {
+    - LOGGER : Logger {static}
+    + RealVideoObject()
+    - heavyInitialConfiguration()
+    + process()
+  }
+  class VideoObjectProxy {
+    - realVideoObject : RealVideoObject
+    + VideoObjectProxy()
+    + getRealVideoObject() : RealVideoObject
+    + process()
+  }
+}
+VideoObjectProxy -->  "-realVideoObject" RealVideoObject
+RealVideoObject ..|> ExpensiveObject 
+VideoObjectProxy ..|> ExpensiveObject 
+@enduml
\ No newline at end of file