@classmethod
def from_isotherm(cls, isotherm, pressure=None, loading=None, isotherm_data
    =None, pressure_key=None, loading_key=None, other_keys=None):
    """
        Construct a point isotherm using a parent isotherm as the template for
        all the parameters.

        Parameters
        ----------
        isotherm : Isotherm
            An instance of the Isotherm parent class.
        pressure : list
            Create an isotherm directly from an array. Values for pressure.
            If the ``isotherm_data`` dataframe is specified, these values are ignored.
        loading : list
            Create an isotherm directly from an array. Values for loading.
            If the ``isotherm_data`` dataframe is specified, these values are ignored.
        isotherm_data : DataFrame
            Pure-component adsorption isotherm data.
        loading_key : str
            Column of the pandas DataFrame where the loading is stored.
        pressure_key : str
            Column of the pandas DataFrame where the pressure is stored.
        """
    iso_params = isotherm.to_dict()
    iso_params['pressure'] = pressure
    iso_params['loading'] = loading
    iso_params['isotherm_data'] = isotherm_data
    iso_params['pressure_key'] = pressure_key
    iso_params['loading_key'] = loading_key
    iso_params['other_keys'] = other_keys
    return cls(**iso_params)
