'Deserialize the request body to the specified content type.
Uses self._serialization_metadata if it exists, which is a dict mapping
MIME types to information needed to serialize to that type.'

def _deserialize(self, data, content_type):

    _metadata = getattr(type(self), '_serialization_metadata', {})
    serializer = Serializer(_metadata)
    return serializer.deserialize(data, content_type)['body']
