def METHOD_NAME(
    self, world_to_data: Affine, round_index: bool = True
) -> Tuple[Union[int, slice], ...]:
    """Transforms this into indices that can be used to slice layer data.
    The elements in non-displayed dimensions will be real numbers.
    The elements in displayed dimensions will be ``slice(None)``.
    """
    if not self.is_orthogonal(world_to_data):
        warnings.warn(
            trans._(
                'Non-orthogonal slicing is being requested, but is not fully supported. Data is displayed without applying an out-of-slice rotation or shear component.',
                deferred=True,
            ),
            category=UserWarning,
        )
    slice_world_to_data = world_to_data.set_slice(self.not_displayed)
    world_pts = [self.point[ax] for ax in self.not_displayed]
    data_pts = slice_world_to_data(world_pts)
    if round_index:
        # A round is taken to convert these values to slicing integers
        data_pts = np.round(data_pts).astype(int)
    indices = [slice(None)] * self.ndim
    for i, ax in enumerate(self.not_displayed):
        indices[ax] = data_pts[i]
    return tuple(indices)