class_docstr: Test advanced pickler and unpickler functionality supported by the
  .hvz format.
code: def test_pickler_save_load_single_layout(self, tmp_path):
      single_layout = Layout([self.image1])
      Pickler.save(
          single_layout,
          tmp_path / "test_pickler_save_load_single_layout",
          info={"info": "example"},
          key={1: 2},
      )
  
      entries = Unpickler.entries(
          tmp_path / "test_pickler_save_load_single_layout.hvz"
      )
      assert entries == ["Image.I(L)"]
      loaded = Unpickler.load(
          tmp_path / "test_pickler_save_load_single_layout.hvz",
          entries=["Image.I(L)"],
      )
      assert_element_equal(single_layout, loaded)
  
imports: import numpy
  from holoviews import Image, Layout
  from holoviews.core.io import Deserializer, Pickler, Serializer, Unpickler
  from holoviews.element.comparison import assert_element_equal
label_desc: Use image node_id 7 for calling the TestPicklerAdvanced obj's underlying member method code with example usage: obj.test_pickler_save_load_single_layout(tmp_path) without return types