You can enter invalid characters

[xWo0d]

For example from my app:
<com.github.pinball83.maskededittext.MaskedEditText
android:id="@+id/met_series_number"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="number"
app:mask="S: cccc N: cccccc"
app:notMaskedSymbol="c"
android:singleLine="true"
android:hint="@string/passport_field_number"/>

At runtime i can enter . , : spaces. And i can enter N, S symbols from keyboard at genymotion emulator runtime.