class_docstr: A utility class to help declare input signatures of composable pipelines.
class_docstr_tok: ["A","utility","class","to","help","declare","input","signatures","of","composable","pipelines","."]
code: def __getitem__(self, key) -> channel.PipelineInputChannel:
      return self._wrapped_inputs[key]
  
imports: import copy
  import enum
  from typing import Any, Collection, Dict, Iterable, Iterator, List, Optional, Tuple, Union, cast
  import warnings
  from tfx.dsl.compiler import constants
  from tfx.dsl.components.base import base_node
  from tfx.dsl.components.base import executor_spec
  from tfx.dsl.context_managers import dsl_context_registry
  from tfx.dsl.experimental.conditionals import conditional
  from tfx.dsl.placeholder import placeholder
  from tfx.orchestration import data_types
  from tfx.orchestration import metadata
  from tfx.types import channel
  from tfx.types import channel_utils
  from tfx.utils import doc_controls
  from tfx.utils import topsort
  from google.protobuf import message
label_desc: Use image node_id 4 for calling the PipelineInputs obj's underlying member method code with example usage: obj.__getitem__(key) and returns: self