docs: private String unif( DroolsEditorType edType ) throws RecognitionException {
          Token label = match( input,
                               DRL5Lexer.ID,
                               null,
                               null,
                               edType );
          if ( state.failed ) return null;
  
          match( input,
                 DRL5Lexer.UNIFY,
                 null,
                 null,
                 DroolsEditorType.SYMBOL );
          if ( state.failed ) return null;
  
          return label.getText();
      }