docs: def from_df(cls, df_long, df_short):
          """
          Builds TripleOrbitPopulation from DataFrame
  
          ``DataFrame`` objects must be of appropriate form to pass
          to :func:`OrbitPopulation.from_df`.
  
          :param df_long, df_short:
              :class:`pandas.DataFrame` objects to pass to
              :func:`OrbitPopulation.from_df`.
  
          """
          pop = cls(1,1,1,1,1) #dummy population
          pop.orbpop_long = OrbitPopulation.from_df(df_long)
          pop.orbpop_short = OrbitPopulation.from_df(df_short)
          return pop