def METHOD_NAME(self, x_shift, y_shift, pixel_unit=False):
    """Shifts the coordinate system.
    :param x_shift: shift in x (or RA)
    :param y_shift: shift in y (or DEC)
    :param pixel_unit: bool, if True, units of pixels in input, otherwise RA/DEC
    :return: updated data class with change in coordinate system
    """
    self._shift_coordinates(x_shift, y_shift, pixel_unit)