docs: public static Operator getReversedOperator(Operator e) {
          if ( e.equals( Operator.NOT_EQUAL ) ) {
              return Operator.EQUAL;
          } else if ( e.equals( Operator.EQUAL ) ) {
              return Operator.NOT_EQUAL;
          } else if ( e.equals( Operator.GREATER ) ) {
              return Operator.LESS_OR_EQUAL;
          } else if ( e.equals( Operator.LESS ) ) {
              return Operator.GREATER_OR_EQUAL;
          } else if ( e.equals( Operator.GREATER_OR_EQUAL ) ) {
              return Operator.LESS;
          } else if ( e.equals( Operator.LESS_OR_EQUAL ) ) {
              return Operator.GREATER;
          } else {
              return Operator.determineOperator( e.getOperatorString(),
                                                 !e.isNegated() );
          }
      }