code: def define(self):
          
          self.collections = []
  
          self.camera_collection = \
              SimpleCollection(filename=os.path.join(self.directory, "devices.dat"),
                               row_classes=[
                  DataModel.EmptyRow,
                  DataModel.RTSPCameraRow,
                  DataModel.USBCameraRow
              ]
              )
          self.collections.append(self.camera_collection)
  
          self.config_collection = \
              SimpleCollection(filename=os.path.join(self.directory, "config.dat"),
                               row_classes=[  # we could dump here all kinds of info related to different kind of configuration forms
                  DataModel.MemoryConfigRow
              ]
              )
          self.collections.append(self.config_collection)
docs: Define column patterns and collections