def METHOD_NAME(self):
    with self._open_file(self.filename) as data_file:
        for array_key, ds_name in self.datasets.items():
            if ds_name not in data_file:
                raise RuntimeError("%s not in %s" % (ds_name, self.filename))
            spec = self.__read_spec(array_key, data_file, ds_name)
            self.provides(array_key, spec)