code: private static boolean revComparisonsMatch(AbstractExpression e1, AbstractExpression e2) {
          return e1 instanceof ComparisonExpression &&
                  e1.getExpressionType() == ComparisonExpression.reverses.get(e2.getExpressionType()) &&
                  new FilterMatcher(((ComparisonExpression) e1).reverseOperator(), e2).match();
      }
docs: Checks whether two expressions are comparisons, and are equivalent by reversing one, e.g. "a >= b" vs. "b <= a".
  @param e1 First expression
  @param e2 second expression
  @return Whether both are comparisons, and reversing first comparison equals the second.