code: def zGetSurfaceData(self, surfNum):
          
          if self.pMode == 0: # Sequential mode
              surf_data = _co.namedtuple('surface_data', ['radius', 'thick', 'material', 'semidia', 
                                                          'conic', 'comment'])
              surf = self.pLDE.GetSurfaceAt(surfNum)
              return surf_data(surf.pRadius, surf.pThickness, surf.pMaterial, surf.pSemiDiameter,
                               surf.pConic, surf.pComment)
          else:
              raise NotImplementedError('Function not implemented for non-sequential mode')
docs: Return surface data