code: def test_destroy(self) -> None:
      d = Document()
      dm = d.models
      assert len(dm) == 0
  
      m1 = Div()
      m2 = Div()
      m3 = Div()
  
      d.add_root(m1)
      d.add_root(m2)
      d.add_root(m3)
      for m in [m1, m2, m3]:
          assert m._document is d
  
      assert dm.destroy() is None
  
      assert not hasattr(dm, "_models")
      assert not hasattr(dm, "_models_by_name")
  
      for m in [m1, m2, m3]:
          assert m._document is None
  
imports: from __future__ import annotations
  import pytest
  import gc
  from unittest.mock import MagicMock, patch
  from bokeh.core.has_props import Local
  from bokeh.core.properties import Instance, Nullable
  from bokeh.core.types import ID
  from bokeh.document import Document
  from bokeh.model import Model
  from bokeh.models import Div, Row
  import bokeh.document.models
label_desc: Use image node_id 6 for calling the TestDocumentModelManager obj's underlying member method code with example usage: obj.test_destroy() without return types