@classmethod
def extract(cls, ds, ds_slice, scale_attr='scale_factor', add_attr=
    'add_offset', unscale=True):
    """
        Extract data from Resource Dataset

        Parameters
        ----------
        ds : h5py.dataset
            Open .h5 dataset instance to extract data from
        ds_slice : slice | list | ndarray
            slice, list, or vector of points to extract
        scale_attr : str, optional
            Name of scale factor attribute, by default 'scale_factor'
        add_attr : str, optional
            Name of add offset attribute, by default 'add_offset'
        unscale : bool, optional
            Flag to unscale dataset data, by default True
        """
    dset = cls(ds, scale_attr=scale_attr, add_attr=add_attr, unscale=unscale)
    return dset[ds_slice]
