docs: def register_forward_model(self, pid_mag, pid_pha):
          """Register parameter sets as the forward models for magnitude and
          phase
  
          Parameters
          ----------
          pid_mag: int
              parameter id corresponding to the magnitude model
          pid_pha: int
              parameter id corresponding to the phase model
          """
          self.register_magnitude_model(pid_mag)
          self.register_phase_model(pid_pha)