code: def check_config(config):
      
      for section, expected_section_keys in SECTION_KEYS.items():
          section_content = config.get(section)
          if not section_content:
              raise ConfigurationError("Config file badly formed! Section {} is missing."
                                       .format(section))
          elif not _section_is_healthy(section_content, expected_section_keys):
              raise ConfigurationError("The {} section of the configuration file is badly formed!"
                                       .format(section))
docs: Check that all sections of the config contain the keys that they should.
  
      Args:
          config (defaultdict): A defaultdict.
      Raises:
          ConfigurationError