code: def _pbm(h):
      """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/email/mime/image.py
imports: from email import encoders
  from email.mime.nonmultipart import MIMENonMultipart
label_desc: Use image node_id 8 for calling a global function with example usage: _pbm(h) and returns: str