text: 
  from cc3d.core.PySteppables import *
  
  class diffusion_steady_state_ext_potential_3DSteppable(SteppableBasePy):
  
      def __init__(self,frequency=1):
  
          SteppableBasePy.__init__(self,frequency)
  
      def start(self):
          """
          any code in the start function runs before MCS=0
          """
  
      def step(self,mcs):
          """
          type here the code that will run every frequency MCS
          :param mcs: current Monte Carlo step
          """
  
      def finish(self):
          """
          Finish Function is called after the last MCS
          """
  
  
  