code: def test_remove_and_put_buffers(self):
      mv1 = memoryview(b"test1")
      mv2 = memoryview(b"test2")
      state = {
          "plain": [0, "text"],  # should not get removed
          "x": {"ar": mv1},  # should result in an empty dict
          "y": {"shape": (10, 10), "data": mv1},
          "z": (mv1, mv2),  # tests tuple assignment
          "top": mv1,  # test a top level removal
          "deep": {"a": 1, "b": [0, {"deeper": mv2}]},
      }  # deeply nested
      plain = state["plain"]
      x = state["x"]
      y = state["y"]
      y_shape = y["shape"]
      state_before = state
      state, buffer_paths, buffers = _remove_buffers(state)
  
      # check if buffers are removed
      self.assertIn("plain", state)
      self.assertIn("shape", state["y"])
      self.assertNotIn("ar", state["x"])
      self.assertEqual(state["x"], {})
      self.assertNotIn("data", state["y"])
      self.assertNotIn(mv1, state["z"])
      self.assertNotIn(mv1, state["z"])
      self.assertNotIn("top", state)
      self.assertIn("deep", state)
      self.assertIn("b", state["deep"])
      self.assertNotIn("deeper", state["deep"]["b"][1])
  
      # check that items that didn't need change aren't touched
      self.assertIsNot(state, state_before)
      self.assertIs(state["plain"], plain)
      self.assertIsNot(state["x"], x)
      self.assertIsNot(state["y"], y)
      self.assertIs(state["y"]["shape"], y_shape)
  
      # check that the buffer paths really point to the right buffer
      for path, buffer in [
          (["x", "ar"], mv1),
          (["y", "data"], mv1),
          (["z", 0], mv1),
          (["z", 1], mv2),
          (["top"], mv1),
          (["deep", "b", 1, "deeper"], mv2),
      ]:
          self.assertIn(path, buffer_paths, "%r not in path" % path)
          index = buffer_paths.index(path)
          self.assertEqual(buffer, buffers[index])
  
      # and check that we can put it back together again
      _put_buffers(state, buffer_paths, buffers)
      # we know that tuples get converted to list, so help the comparison by changing the tuple to a list
      state_before["z"] = list(state_before["z"])
      self.assertEqual(state_before, state)
  
imports: import array
  import datetime
  import pytest
  from unittest import TestCase
  from traitlets import HasTraits, Int, TraitError
  from traitlets.tests.test_traitlets import TraitTestBase
  from ipywidgets import Color, NumberFormat
  from ipywidgets.widgets.widget import _remove_buffers, _put_buffers
  from ipywidgets.widgets.trait_types import date_serialization, TypedTuple
label_desc: Use image node_id 1 for calling the TestBuffers obj's underlying member method code with example usage: obj.test_remove_and_put_buffers() without return types