diff --git a/abstract-document/src/main/java/com/iluwatar/abstractdocument/AbstractDocument.java b/abstract-document/src/main/java/com/iluwatar/abstractdocument/AbstractDocument.java
index 70190604150b..4ad3ce84085c 100644
--- a/abstract-document/src/main/java/com/iluwatar/abstractdocument/AbstractDocument.java
+++ b/abstract-document/src/main/java/com/iluwatar/abstractdocument/AbstractDocument.java
@@ -75,16 +75,16 @@ private String buildStringRepresentation() {
     builder.append(getClass().getName()).append("[");
 
     // Explaining variable for document properties map
-    Map<String, Object> documentProperties = this.documentProperties;
+    Map<String, Object> mpdocumentProperties = this.documentProperties;
 
     // Explaining variable for the size of document properties map
-    int numProperties = documentProperties.size();
+    int numProperties = mpdocumentProperties.size();
 
     // Explaining variable for tracking the current property index
     int currentPropertyIndex = 0;
 
     // Iterate over document properties map
-    for (Map.Entry<String, Object> entry : documentProperties.entrySet()) {
+    for (Map.Entry<String, Object> entry : mpdocumentProperties.entrySet()) {
       String key = entry.getKey();
       Object value = entry.getValue();
 
diff --git a/abstract-document/src/test/java/com/iluwatar/abstractdocument/AbstractDocumentTest.java b/abstract-document/src/test/java/com/iluwatar/abstractdocument/AbstractDocumentTest.java
index a86e6273d5b5..2b932727bd58 100644
--- a/abstract-document/src/test/java/com/iluwatar/abstractdocument/AbstractDocumentTest.java
+++ b/abstract-document/src/test/java/com/iluwatar/abstractdocument/AbstractDocumentTest.java
@@ -75,9 +75,9 @@ void shouldRetrieveEmptyStreamForNonExistingChildren() {
   @Test
   void shouldIncludePropsInToString() {
     var props = Map.of(KEY, (Object) VALUE);
-    var document = new DocumentImplementation(props);
-    assertTrue(document.toString().contains(KEY));
-    assertTrue(document.toString().contains(VALUE));
+    var varDocument = new DocumentImplementation(props);
+    assertTrue(varDocument.toString().contains(KEY));
+    assertTrue(varDocument.toString().contains(VALUE));
   }
 
   @Test
diff --git a/anti-corruption-layer/src/main/java/com/iluwatar/corruption/system/DataStore.java b/anti-corruption-layer/src/main/java/com/iluwatar/corruption/system/DataStore.java
index e9fdaa14ec1f..a7d063710c68 100644
--- a/anti-corruption-layer/src/main/java/com/iluwatar/corruption/system/DataStore.java
+++ b/anti-corruption-layer/src/main/java/com/iluwatar/corruption/system/DataStore.java
@@ -34,7 +34,7 @@
 public abstract class DataStore<V> {
   private final HashMap<String, V> inner;
 
-  public DataStore() {
+  protected DataStore() {
     inner = new HashMap<>();
   }
 
diff --git a/serialized-lob/src/main/java/com/iluwatar/slob/dbservice/DatabaseService.java b/serialized-lob/src/main/java/com/iluwatar/slob/dbservice/DatabaseService.java
index ea54592c99d1..66555a849b1b 100644
--- a/serialized-lob/src/main/java/com/iluwatar/slob/dbservice/DatabaseService.java
+++ b/serialized-lob/src/main/java/com/iluwatar/slob/dbservice/DatabaseService.java
@@ -92,7 +92,7 @@ public void startupService()
       throws SQLException {
     try (var connection = dataSource.getConnection();
         var statement = connection.createStatement()) {
-      if (dataTypeDb.equals("BINARY")) {
+      if (dataTypeDb.equals(BINARY_DATA)) {
         statement.execute(CREATE_BINARY_SCHEMA_DDL);
       } else {
         statement.execute(CREATE_TEXT_SCHEMA_DDL);
diff --git a/serialized-lob/src/main/java/com/iluwatar/slob/lob/Forest.java b/serialized-lob/src/main/java/com/iluwatar/slob/lob/Forest.java
index 1c14d55debd8..ae0f2ce9a9a2 100644
--- a/serialized-lob/src/main/java/com/iluwatar/slob/lob/Forest.java
+++ b/serialized-lob/src/main/java/com/iluwatar/slob/lob/Forest.java
@@ -48,6 +48,7 @@
 public class Forest implements Serializable {
 
   private String name;
+  private String NEWLINE = "\n--------------------------\n";
   private Set<Animal> animals = new HashSet<>();
   private Set<Plant> plants = new HashSet<>();
 
@@ -105,16 +106,16 @@ public String toString() {
     sb.append("Forest Name = ").append(name).append("\n");
     sb.append("Animals found in the ").append(name).append(" Forest: \n");
     for (Animal animal : animals) {
-      sb.append("\n--------------------------\n");
+      sb.append(NEWLINE);
       sb.append(animal.toString());
-      sb.append("\n--------------------------\n");
+      sb.append(NEWLINE);
     }
     sb.append("\n");
     sb.append("Plants in the ").append(name).append(" Forest: \n");
     for (Plant plant : plants) {
-      sb.append("\n--------------------------\n");
+      sb.append(NEWLINE);
       sb.append(plant.toString());
-      sb.append("\n--------------------------\n");
+      sb.append(NEWLINE);
     }
     return sb.toString();
   }
diff --git a/type-object/src/main/java/com/iluwatar/typeobject/CandyGame.java b/type-object/src/main/java/com/iluwatar/typeobject/CandyGame.java
index 85d39c8c79c3..55475c4b9473 100644
--- a/type-object/src/main/java/com/iluwatar/typeobject/CandyGame.java
+++ b/type-object/src/main/java/com/iluwatar/typeobject/CandyGame.java
@@ -79,23 +79,23 @@ void printGameStatus() {
 
   List<Cell> adjacentCells(int y, int x) {
     var adjacent = new ArrayList<Cell>();
-    if (y == 0) {
+    if (y == 0 && cells.length > 0) {
       adjacent.add(this.cells[1][x]);
     }
-    if (x == 0) {
+    if (x == 0 & cells.length > 0) {
       adjacent.add(this.cells[y][1]);
     }
-    if (y == cells.length - 1) {
+    if ((cells.length > 0) && (y == cells.length - 1)) {
       adjacent.add(this.cells[cells.length - 2][x]);
     }
-    if (x == cells.length - 1) {
+    if ((cells.length > 0) && (x == cells.length - 1)) {
       adjacent.add(this.cells[y][cells.length - 2]);
     }
-    if (y > 0 && y < cells.length - 1) {
+    if ((cells.length > 0) && y > 0 && y < cells.length - 1) {
       adjacent.add(this.cells[y - 1][x]);
       adjacent.add(this.cells[y + 1][x]);
     }
-    if (x > 0 && x < cells.length - 1) {
+    if ((cells.length > 0) && x > 0 && x < cells.length - 1) {
       adjacent.add(this.cells[y][x - 1]);
       adjacent.add(this.cells[y][x + 1]);
     }
@@ -103,23 +103,25 @@ List<Cell> adjacentCells(int y, int x) {
   }
 
   boolean continueRound() {
-    for (var i = 0; i < this.cells.length; i++) {
-      if (this.cells[cells.length - 1][i].candy.getType().equals(Type.REWARD_FRUIT)) {
-        return true;
+    if(this.cells.length >0) {
+      for (var i = 0; i < this.cells.length; i++) {
+        if (this.cells[cells.length - 1][i].candy.getType().equals(Type.REWARD_FRUIT)) {
+          return true;
+        }
       }
-    }
-    for (var i = 0; i < this.cells.length; i++) {
-      for (var j = 0; j < this.cells.length; j++) {
-        if (!this.cells[i][j].candy.getType().equals(Type.REWARD_FRUIT)) {
-          var adj = adjacentCells(i, j);
-          for (Cell cell : adj) {
-            if (this.cells[i][j].candy.name.equals(cell.candy.name)) {
-              return true;
+      for (var i = 0; i < this.cells.length; i++) {
+        for (var j = 0; j < this.cells.length; j++) {
+          if (!this.cells[i][j].candy.getType().equals(Type.REWARD_FRUIT)) {
+            var adj = adjacentCells(i, j);
+            for (Cell cell : adj) {
+              if (this.cells[i][j].candy.name.equals(cell.candy.name)) {
+                return true;
+              }
             }
           }
         }
-      }
     }
+  }
     return false;
   }