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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def check_config(config):
 """Check that all sections of the config contain the keys that they should. Args: config (defaultdict):
 A defaultdict. Raises: ConfigurationError """

    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))