code: def GetServiceDll(self, key):
      
      parameters_key = key.GetSubkeyByName('Parameters')
      if not parameters_key:
        return None
  
      service_dll = parameters_key.GetValueByName('ServiceDll')
      if not service_dll:
        return None
  
      return service_dll.GetDataAsObject()
docs: Get the Service DLL for a service, if it exists.
  
      Checks for a ServiceDLL for in the Parameters subkey of a service key in
      the Registry.
  
      Args:
        key (dfwinreg.WinRegistryKey): a Windows Registry key.
  
      Returns:
        str: path of the service DLL or None.