code: def set_defaults(self):
          
          self['mswitch'] = 1
          self['elem'] = '../grid/elem.dat'
          self['elec'] = '../grid/elec.dat'
          self['volt'] = '../mod/volt.dat'
          self['inv_dir'] = '../inv'
          self['diff_inv'] = 'F ! difference inversion?'
          self['iseed_var'] = 'iseed variance'
          self['cells_x'] = '0    ! # cells in x-direction'
          self['cells_z'] = '-1    ! # cells in z-direction'
          self['ani_x'] = '1.000  ! smoothing parameter in x-direction'
          self['ani_z'] = '1.000  ! smoothing parameter in z-direction'
          self['max_it'] = '20    ! max. nr of iterations'
          self['dc_inv'] = 'F     ! DC inversion?'
          self['robust_inv'] = 'T     ! robust inversion?'
          self['fpi_inv'] = 'F     ! final phase improvement?'
          self['mag_rel'] = '5'
          self['mag_abs'] = '1e-3'
          self['pha_a1'] = 0
          self['pha_b'] = 0
          self['pha_rel'] = 0
          self['pha_abs'] = 0
          self['hom_bg'] = 'F'
          self['hom_mag'] = '10.00'
          self['hom_pha'] = '0.00'
          self['another_ds'] = 'F'
          self['d2_5'] = '1'
          self['fic_sink'] = 'F'
          self['fic_sink_node'] = '10000'
          self['boundaries'] = 'F'
          self['boundaries_file'] = 'boundary.dat'
          self['mswitch2'] = '1'
          self['lambda'] = 'lambda'
docs: Fill the dictionary with all defaults