code: def scalar_names(self):
          
          names = []
          for i in range(self.GetPointData().GetNumberOfArrays()):
              names.append(self.GetPointData().GetArrayName(i))
          for i in range(self.GetCellData().GetNumberOfArrays()):
              names.append(self.GetCellData().GetArrayName(i))
          try:
              names.remove(self.active_scalar_name)
              names.insert(0, self.active_scalar_name)
          except ValueError:
              pass
          return names
docs: A list of scalar names for the dataset. This makes
          sure to put the active scalar's name first in the list.