def METHOD_NAME(self):
    if not self.param_viewer.index_selection:
        return
    tensorlib, _ = get_backend()
    self.normsys_mask = tensorlib.tile(
        tensorlib.astensor(self._normsys_mask, dtype="bool"),
        (1, 1, self.batch_size or 1, 1),
    )
    self.normsys_default = tensorlib.ones(self.normsys_mask.shape)
    if self.batch_size is None:
        self.indices = tensorlib.reshape(
            self.param_viewer.indices_concatenated, (-1, 1)
        )