message: Change Ragged's _is_graph_tensor to check _row_splits, which is always a tf.Tensor.
diff: @@ -1860,7 +1860,7 @@ class RaggedTensor(composite_tensor.CompositeTensor):
  @property
  def _is_graph_tensor(self):
  - return hasattr(self._values, "graph")
  + return hasattr(self._row_splits, "graph")
  def consumers(self):
  return self._consumers()
  