docs: def add_homogeneous_model(self, magnitude, phase=0):
          """Add a homogeneous resistivity model to the tomodir. This is useful
          for synthetic measurements.
  
          Parameters
          ----------
          magnitude : float
              magnitude [Ohm m] value of the homogeneous model
          phase : float, optional
              phase [mrad] value of the homogeneous model
  
  
          Returns
          -------
          pid_mag : int
              ID value of the parameter set of the magnitude model
          pid_pha : int
              ID value of the parameter set of the phase model
  
          Note that the parameter sets are automatically registered as the
          forward models for magnitude and phase values.
          """
          if self.assignments['forward_model'] is not None:
              print('model already set, will overwrite')
  
          # generate distributions
          magnitude_model = np.ones(self.grid.nr_of_elements) * magnitude
          phase_model = np.ones(self.grid.nr_of_elements) * phase
          pid_mag = self.parman.add_data(magnitude_model)
          pid_pha = self.parman.add_data(phase_model)
  
          self.assignments['forward_model'] = [pid_mag, pid_pha]
          return pid_mag, pid_pha