code: def _parse_placeholder_types(values):
      """Extracts placeholder types from a comma separate list."""
      values = [int(value) for value in values.split(",")]
      return values if len(values) > 1 else values[0]
  
file_path: tensorflow-upstream/tensorflow/python/tools/optimize_for_inference.py
imports: import argparse
  import os
  import sys
  from absl import app
  from google.protobuf import text_format
  from tensorflow.core.framework import graph_pb2
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import graph_io
  from tensorflow.python.platform import gfile
  from tensorflow.python.tools import optimize_for_inference_lib
label_desc: Use image node_id 2 for calling a global function with example usage: _parse_placeholder_types(values) and returns: unknown