code: public BooleanExpression ne(T right) {
          if (right == null) {
              throw new IllegalArgumentException("ne(null) is not allowed. Use isNotNull() instead");
          } else {
              return ne(ConstantImpl.create(right));
          }
      }
docs: Create a {@code this <> right} expression
  
  @param right rhs of the comparison
  @return this != right