code: def insert(self, index, item):
          
          if not is_any(item):
              raise MemberTypeError(self, item, member=len(self))
          self._data.insert(index, item)
docs: Inserts the *item* before the *index* into the `Sequence`.
  
          :param int index: `Sequence` index.
          :param item: any :class:`Structure`, :class:`Sequence`, :class:`Array`
              or :class:`Field` instance.