code: def build(self, input_shape=None):
      if self.built:
          return
      self.built = True
      if getattr(self, "span_predictor", None) is not None:
          with tf.name_scope(self.span_predictor.name):
              self.span_predictor.build(None)
  
imports: from __future__ import annotations
  from dataclasses import dataclass
  from typing import Tuple, Union
  import tensorflow
  from ...modeling_tf_outputs import TFBaseModelOutputWithPooling
  from ...modeling_tf_utils import TFModelInputType, TFPreTrainedModel, get_initializer, shape_list, unpack_inputs
  from ...utils import ModelOutput, add_start_docstrings, add_start_docstrings_to_model_forward, logging, replace_return_docstrings
  from ..bert.modeling_tf_bert import TFBertMainLayer
  from .configuration_dpr import DPRConfig
label_desc: Use image node_id 4 for calling the TFDPRReader obj's underlying member method code with example usage: obj.build(input_shape) without return types