code: def buildkite_echo(
      message: str, print_fn: Callable[[str], None] = print
  ):
      if "BUILDKITE" in os.environ:
          print_fn(message)
  
imports: import os
  from typing import Optional, Callable
label_desc: Use image node_id 1 for calling a global function with example usage: buildkite_echo(message, print_fn) without return types