public GremlinExpression(ExpressionFragment left, ExpressionSemantics semantics, ExpressionFragment right)
 {
     if (!(left is ParameterExpressionFragment) && right is ParameterExpressionFragment)
     {
         Left      = right;
         Semantics = semantics.Flip();
         Right     = left;
     }
     else
     {
         Left      = left;
         Right     = right;
         Semantics = semantics;
     }
 }