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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 extract_root_meta(cls, serializer, resource):
 """ Calls a `get_root_meta` function on a serializer, if it exists. """

        many = False
        if hasattr(serializer, 'child'):
            many = True
            serializer = serializer.child

        data = {}
        if getattr(serializer, 'get_root_meta', None):
            json_api_meta = serializer.get_root_meta(resource, many)
            assert isinstance(json_api_meta, dict), 'get_root_meta must return a dict'
            data.update(json_api_meta)
        return data