code: def _has_valid_positional_setitem_indexer(self, indexer):
          
          if isinstance(indexer, dict):
              raise IndexError("{0} cannot enlarge its target object"
                               .format(self.name))
          else:
              if not isinstance(indexer, tuple):
                  indexer = self._tuplify(indexer)
              for ax, i in zip(self.obj.axes, indexer):
                  if isinstance(i, slice):
                      # should check the stop slice?
                      pass
                  elif is_list_like_indexer(i):
                      # should check the elements?
                      pass
                  elif is_integer(i):
                      if i >= len(ax):
                          raise IndexError("{name} cannot enlarge its target "
                                           "object".format(name=self.name))
                  elif isinstance(i, dict):
                      raise IndexError("{name} cannot enlarge its target object"
                                       .format(name=self.name))
  
          return True
docs: validate that an positional indexer cannot enlarge its target
          will raise if needed, does not modify the indexer externally