code: private function isInvalidIn($node)
      {
          return ($node instanceof Expr\Variable) === false
          && ($node instanceof Expr\ClassConstFetch) === false
          && ($node instanceof Expr\Cast) === false
          && ($node instanceof Expr\ConstFetch) === false
          && ($node instanceof Expr\StaticCall) === false
          && ($node instanceof Expr\PropertyFetch) === false
          && ($node instanceof Expr\ArrayDimFetch) === false
          && ($node instanceof Expr\Assign) === false
          && ($node instanceof BinaryOp\Minus) === false
          && ($node instanceof BinaryOp\Plus) === false
          && ($node instanceof BinaryOp\Mod) === false
          && ($node instanceof Scalar) === false
          && $node !== null;
      }
docs: @param \PhpParser\Node $node
  
  @return bool