code: def parse150(resp):
      """Parse the '150' response for a RETR request.
      Returns the expected transfer size or None; size is not guaranteed to
      be present in the 150 message.
      """
      if resp[:3] != "150":
          raise error_reply(resp)
      global _150_re
      if _150_re is None:
          import re
  
          _150_re = re.compile(
              r"150 .* \((\d+) bytes\)", re.IGNORECASE | re.ASCII
          )
      m = _150_re.match(resp)
      if not m:
          return None
      return int(m.group(1))
  
imports: import sys
  import socket
  from socket import _GLOBAL_DEFAULT_TIMEOUT
label_desc: Use image node_id 1 for calling a global function with example usage: parse150(resp) and returns: int, None