class_docstr: Import tensorflow model to nnp model.
      
class_docstr_tok: ["Import","tensorflow","model","to","nnp","model","."]
code: def execute(self):
      if self._tf_format == "TF_PB":
          graph_def = graph_pb2.GraphDef()
          with tf.io.gfile.GFile(self._tf_file, "rb") as f:
              graph_def.ParseFromString(f.read())
          inputs, outputs = find_out_terminal_node(
              graph_def, postfix=True
          )
          graph_def, inputs, outputs = tf_loader.from_graphdef(
              self._tf_file, inputs, outputs
          )
      elif self._tf_format == "SAVED_MODEL":
          graph_def, inputs, outputs = tf_loader.from_saved_model(
              self._tf_file, None, None
          )
      else:
          if self._outputs is None:
              raise ImportError("Missing '--outputs' parameter.")
          if self._inputs is None:
              raise ImportError("Missing '--inputs' parameter.")
  
          inputs = [i + ":0" for i in self._inputs.split(",")]
          outputs = [i + ":0" for i in self._outputs.split(",")]
          if self._tf_format == "TF_CKPT_V1":
              graph_def = self.load_checkpoint_v1()
          elif self._tf_format == "TF_CKPT_V2":
              graph_def, inputs, outputs = tf_loader.from_checkpoint(
                  self._tf_file, inputs, outputs
              )
      onnx_model = self.convert_to_onnx(graph_def, inputs, outputs)
      onnx_importer = OnnxImporter()
      onnx_importer.import_from_onnx_model(onnx_model)
      return onnx_importer.execute()
  
file_path: nnabla/python/src/nnabla/utils/converter/tensorflow/importer.py
imports: import os
  import tensorflow
  import tflite
  import tflite2onnx
  from tensorflow.core.framework import graph_pb2
  from tensorflow.python.tools import freeze_graph
  from tf2onnx import constants, tf_loader, optimizer
  from tf2onnx.tfonnx import process_tf_graph
  from .common import find_out_terminal_node
  from ..onnx import OnnxImporter
label_desc: Use image node_id 4 for calling the TensorflowImporter obj's underlying member method code with example usage: obj.execute() and returns: onnx_importer