old_contents: from ophyd.controls import EpicsMotor, PVPositioner
  
  
  tth = EpicsMotor('XF:28IDC-ES:1{Dif-Ax:2ThI}Mtr', name='tth')
  
  cs700 = PVPositioner('XF:28IDC-ES:1{Env:01}T-SP',
                       readback='XF:28IDC-ES:1{Env:01}T-I',
                       put_complete=True)
  
  
new_contents: from ophyd.controls import EpicsMotor, PVPositioner
  from ophyd.controls.positioner import MoveStatus,Positioner
  
  
  class NullPositioner(Positioner):
  
      def __init__(self, name=None):
          Positioner.__init__(self)
          self._egu = 'a.u.'
          self._position = 0
  
      def move(self, position, wait=False,
                moved_cb=None, timeout=30.0):
  
          self._position = position
          status = MoveStatus(self, position, done=True)
          self.subscribe(status._finished,
                         event_type=self._SUB_REQ_DONE, run=True)
  
          return status
  
  tth = EpicsMotor('XF:28IDC-ES:1{Dif-Ax:2ThI}Mtr', name='tth')
  
  cs700 = PVPositioner('XF:28IDC-ES:1{Env:01}T-SP',
                       readback='XF:28IDC-ES:1{Env:01}T-I',
                       stop='XF:28IDC-ES:1{Env:01}Cmd-Cmd', stop_val=13,
                       put_complete=True)
  
  nullmtr = NullPositioner(name='nullmtr')
  
subject: Add NullPositioner.