class_docstr: Test advanced pickler and unpickler functionality supported by the
  .hvz format.
code: def setup_method(self):
      self.image1 = Image(np.array([[1, 2], [4, 5]]))
      self.image2 = Image(np.array([[5, 4], [3, 2]]))
  
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 1 for calling the TestPicklerAdvanced obj's underlying member method code with example usage: obj.setup_method() without return types