code: def get_boto_client(
          client,
          region=None,
          aws_access_key_id=None,
          aws_secret_access_key=None,
          aws_session_token=None,
          endpoint_url=None
          ):
      
      cache_key = '{0}:{1}:{2}:{3}'.format(
          client,
          region,
          aws_access_key_id,
          endpoint_url or ''
      )
      if not aws_session_token:
          if cache_key in CLIENT_CACHE:
              return CLIENT_CACHE[cache_key]
      session = get_boto_session(
          region,
          aws_access_key_id,
          aws_secret_access_key,
          aws_session_token
      )
      if not session:
          logging.error("Failed to get {0} client.".format(client))
          return None
  
      CLIENT_CACHE[cache_key] = session.client(
          client,
          endpoint_url=endpoint_url
      )
      return CLIENT_CACHE[cache_key]
docs: Get a boto3 client connection.