code: def build(self, input_shape=None):
      if self.built:
          return
      self.built = True
      if getattr(self, "rag", None) is not None:
          with tf.name_scope(self.rag.name):
              self.rag.build(None)
  
imports: from __future__ import annotations
  import copy
  from dataclasses import dataclass
  from typing import List, Optional, Tuple, Union
  import numpy
  import tensorflow
  from ...configuration_utils import PretrainedConfig
  from ...generation import TFLogitsProcessorList
  from ...modeling_tf_utils import TFCausalLanguageModelingLoss, TFModelInputType, TFPreTrainedModel, shape_list, unpack_inputs
  from ...utils import ModelOutput, add_start_docstrings_to_model_forward, logging, replace_return_docstrings
  from .configuration_rag import RagConfig
  from .retrieval_rag import RagRetriever
label_desc: Use image node_id 16 for calling the TFRagTokenForGeneration obj's underlying member method code with example usage: obj.build(input_shape) without return types