class_docstr: For testing of AttrTree
class_docstr_tok: ["For","testing","of","AttrTree"]
code: def setUp(self):
      self.tree = AttrTree([(("A", "I"), 1), (("B", "II"), 2)])
  
imports: import pytest
  from holoviews.core.element import AttrTree
  from holoviews.element.comparison import ComparisonTestCase
label_desc: Use image node_id 1 for calling the AttrTreeTest obj's underlying member method code with example usage: obj.setUp() without return types