public void METHOD_1 ( TYPE_1 listener ) { if ( ( VAR_1 ) == null ) VAR_1 = new java.util.HashSet < TYPE_1 > ( ) ; VAR_1 . add ( listener ) ; } 

public void METHOD_1 ( TYPE_1 listener ) { if ( ( VAR_1 ) == null ) VAR_1 = new java.util.HashSet < TYPE_1 > ( ) ; if ( ! ( VAR_1 . contains ( listener ) ) ) VAR_1 . add ( listener ) ; } 
