code: def create_headers(version: str):
      # Utility function to create Readme.io headers.
      # We assume the README_API_KEY env var is set since we check outside
      # to show clearer error messages.
      README_API_KEY = os.getenv("README_API_KEY")
      token = base64.b64encode(f"{README_API_KEY}:".encode()).decode()
      return {
          "authorization": f"Basic {token}",
          "x-readme-version": version,
      }
  
imports: import os
  import sys
  import io
  import dataclasses
  import typing
  import base64
  import warnings
  from pathlib import Path
  import requests
  import docspec
  from pydoc_markdown.interfaces import Context, Renderer
  from pydoc_markdown.contrib.renderers.markdown import MarkdownRenderer
label_desc: Use image node_id 1 for calling a global function with example usage: create_headers(version) and returns: dict