class_docstr: The registry that provides name -> object mapping, to support third-party users' custom modules.
  To create a registry (inside segmentron):
  .. code-block:: python
      BACKBONE_REGISTRY = Registry('BACKBONE')
  To register an object:
  .. code-block:: python
      @BACKBONE_REGISTRY.register()
      class MyBackbone():
          ...
  Or:
  .. code-block:: python
      BACKBONE_REGISTRY.register(MyBackbone)
code: def _do_register(self, name, obj):
      assert (
          name not in self._obj_map
      ), "An object named '{}' was already registered in '{}' registry!".format(
          name, self._name
      )
      self._obj_map[name] = obj
  
imports: import functools
  import paddle
  import paddle.nn
  import paddle.nn.functional
label_desc: Use image node_id 2 for calling the Registry obj's underlying member method code with example usage: obj._do_register(name, obj) without return types