<BUG>public void METHOD_1 ( TYPE_1 listener ) {if ( null == listener ) {throw new TYPE_2 ( STRING_1 ) ;BUG> }</BUG></BUG> <BUG> if ( ! ( VAR_1 . contains ( listener ) ) ) {VAR_1 . add ( listener ) ;</BUG> } }
public java.util.Iterator < TYPE_1 > iterator ( ) { return VAR_1 . iterator ( ) ; } 
