code: def test_pbm(h, f):
      """PBM (portable bitmap)"""
      if (
          len(h) >= 3
          and h[0] == ord(b"P")
          and h[1] in b"14"
          and h[2] in b" \t\n\r"
      ):
          return "pbm"
  
file_path: catboost/contrib/tools/python3/src/Lib/imghdr.py
imports: from os import PathLike
  import warnings
label_desc: Use image node_id 7 for calling a global function with example usage: test_pbm(h, f) and returns: str