def METHOD_NAME(xray_structure,
                   exp_i_2pi_functor=None):
  if exp_i_2pi_functor is None:
    return f_calc_modulus_with_std_trigonometry(xray_structure)
  else:
    return f_calc_modulus_with_custom_trigonometry(xray_structure,
                                                   exp_i_2pi_functor)