question: protected void writeTextureMask ( ObjectOutputStream oos , TexturePaint tMask ) throws IOException { boolean writeMask = ( tMask instanceof Serializable ) ; if ( writeMask ) { oos . writeBoolean ( true ) ; oos . writeObject ( ( Serializable ) tMask ) ; } else { oos . writeBoolean ( false ) ; } }
target:  Will only write TexturePaint objects that are Serializable.