code: def _modify_model_input_type(
      model, inference_input_type=dtypes.float32
  ):
      """Modify model input type."""
      if inference_input_type == dtypes.float32:
          return
  
      if not model.signatureDefs:
          _modify_model_input_type_per_subgraph(
              model, 0, -1, inference_input_type
          )
          return
  
      for signature_index, signature_def in enumerate(
          model.signatureDefs
      ):
          _modify_model_input_type_per_subgraph(
              model,
              signature_def.subgraphIndex,
              signature_index,
              inference_input_type,
          )
  
imports: import copy
  import datetime
  import sys
  from absl import logging
  import flatbuffers
  from tensorflow.core.protobuf import config_pb2
  from tensorflow.core.protobuf import meta_graph_pb2
  from tensorflow.lite.python import conversion_metadata_schema_py_generated
  from tensorflow.lite.python import schema_py_generated
  from tensorflow.lite.python import schema_util
  from tensorflow.lite.python import tflite_keras_util
  from tensorflow.lite.python.op_hint import convert_op_hints_to_stubs
  from tensorflow.lite.python.op_hint import find_all_hinted_output_nodes
  from tensorflow.lite.tools import flatbuffer_utils
  from tensorflow.python.eager import function
  from tensorflow.python.framework import convert_to_constants
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import error_interpolation
  from tensorflow.python.grappler import tf_optimizer
  from tensorflow.python.training.saver import export_meta_graph
label_desc: Use image node_id 21 for calling a global function with example usage: _modify_model_input_type(model, inference_input_type) without return types