code: def merge_environment_settings(self, url, proxies, stream, verify, cert):
          
          # Gather clues from the surrounding environment.
          if self.trust_env:
              # Set environment's proxies.
              no_proxy = proxies.get('no_proxy') if proxies is not None else None
              env_proxies = get_environ_proxies(url, no_proxy=no_proxy)
              for (k, v) in env_proxies.items():
                  proxies.setdefault(k, v)
  
              # Look for requests environment configuration and be compatible
              # with cURL.
              if verify is True or verify is None:
                  verify = (os.environ.get('REQUESTS_CA_BUNDLE') or
                            os.environ.get('CURL_CA_BUNDLE'))
  
          # Merge all the kwargs.
          proxies = merge_setting(proxies, self.proxies)
          stream = merge_setting(stream, self.stream)
          verify = merge_setting(verify, self.verify)
          cert = merge_setting(cert, self.cert)
  
          return {'verify': verify, 'proxies': proxies, 'stream': stream,
                  'cert': cert}
docs: Check the environment and merge it with some settings.
  
          :rtype: dict