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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 load_hdf(cls, filename, path=''):
 """ Load TripleOrbitPopulation from saved .h5 file. :param filename: HDF file name. :param path: Path within HDF file where data is stored. """

        df_long = pd.read_hdf(filename,'{}/long/df'.format(path))
        df_short = pd.read_hdf(filename,'{}/short/df'.format(path))
        return cls.from_df(df_long, df_short)