code: def is_elem_ref(elem_ref):
      
      return (
          elem_ref
          and isinstance(elem_ref, tuple)
          and len(elem_ref) == 3
          and (elem_ref[0] == ElemRefObj or elem_ref[0] == ElemRefArr)
      )
docs: Returns true if the elem_ref is an element reference
  
      :param elem_ref:
      :return: