code: def find_config(config_path: str) -> str:
      
      if path.isdir(config_path):  # dir specified instead of config file
          config_path = path.join(config_path, CXF_CONFIG_FILE)
      assert path.exists(config_path), '`{}` does not exist'.format(config_path)
      return config_path
docs: Derive configuration file path from the given path and check its existence.
  
      The given path is expected to be either
  
      1. path to the file
      2. path to a dir, in such case the path is joined with ``CXF_CONFIG_FILE``
  
      :param config_path: path to the configuration file or its parent directory
      :return: validated configuration file path