code: def buffer_to_bytes(buf):
      """Cast a buffer object to bytes"""
      if not isinstance(buf, bytes):
          buf = bytes(buf)
      return buf
  
file_path: catboost/contrib/python/ipython/py2/IPython/utils/py3compat.py
imports: import functools
  import os
  import sys
  import re
  import shutil
  import types
  import platform
  from .encoding import DEFAULT_ENCODING
label_desc: Use image node_id 6 for calling a global function with example usage: buffer_to_bytes(buf) and returns: buf