class_docstr: Base class for a node in TFX pipeline.
class_docstr_tok: ["Base","class","for","a","node","in","TFX","pipeline","."]
code: def upstream_nodes(self):
      return self._upstream_nodes
  
imports: import abc
  import copy
  from typing import Any, Dict, Optional, Type
  from tfx.dsl.components.base import base_driver
  from tfx.dsl.components.base import base_executor
  from tfx.dsl.components.base import executor_spec
  from tfx.dsl.context_managers import dsl_context_registry
  from tfx.dsl.experimental.node_execution_options import utils
  from tfx.utils import deprecation_utils
  from tfx.utils import doc_controls
  from tfx.utils import json_utils
  from tfx.utils import name_utils
label_desc: Use image node_id 14 for calling the BaseNode obj's underlying member method code with example usage: obj.upstream_nodes() and returns: self