@staticmethod
    def __find_implementations():
        """Returns all the concrete subclasses of MetadataExtractor.

        """
        implementations = {}
        for implementation in all_subclasses(MetadataExtractor):
            try:
                implementations[implementation.feature_name()] = implementation
            except __HOLE__:
                pass
        return implementations
dataset/ETHPy150Open c-w/Gutenberg/gutenberg/query/api.py/MetadataExtractor.__find_implementations