class CacheError(Exception): pass
class CacheConfigurationError(CacheError): pass
class LoaderError(Exception): pass
class LoaderConfigurationError(LoaderError): pass
class LoaderNoDataError(LoaderError): pass
class LoaderBadRequestError(LoaderError): pass
class LoaderSourceError(LoaderError): pass
class CacheLoaderConfigurationError(CacheConfigurationError, LoaderConfigurationError): pass
class NoLoadersError(Exception): pass