code: def _normalize_proxies(proxies):
      """Normalize user-supplied `proxies`:
  
      - For `None` -- retrieve System proxies using
        :func:`urllib.request.getproxies`
      - Add `http://` scheme to proxy urls if missing.
      """
      if proxies is None:  # Use system proxy settings
          proxies = getproxies()
      if not proxies:
          return {}  # Disable proxies
  
      normalized = {}
      for scheme, url in proxies.items():
          if url and "://" not in url:
              # Without the scheme there are errors:
              # from aiohttp:
              #   ValueError: Only http proxies are supported
              # from requests (in some envs):
              #   urllib3.exceptions.ProxySchemeUnknown: Not supported
              #   proxy scheme localhost
              url = "http://%s" % url
          normalized[scheme] = url
      return normalized
  
imports: import abc
  import asyncio
  import contextlib
  import email
  import json
  import ssl
  import time
  import warnings
  from socket import timeout
  from ssl import SSLError
  from urllib.error import HTTPError
  from urllib.parse import urlparse
  from urllib.request import HTTPSHandler, ProxyHandler, Request, URLError, build_opener, getproxies
  from geopy.exc import GeocoderParseError, GeocoderServiceError, GeocoderTimedOut, GeocoderUnavailable, GeopyError
  from geopy.util import logger
label_desc: Use image node_id 2 for calling a global function with example usage: _normalize_proxies(proxies) and returns: normalized, dict