input: Write a python function to create an Attr object and check its methods and properties.
  assert attr.name == "class"
  assert attr.value == "test"
  assert attr.specified == True
  assert attr.nodeType == Node.ATTRIBUTE_NODE
  assert attr.parentNode == parent_node
output: def create_attr_object(parent_node):
      from xml.dom.minidom import Attr, Node
      
      attr = Attr("class")
      attr.value = "test"
      attr.specified = True
      attr.nodeType = Node.ATTRIBUTE_NODE
      attr.parentNode = parent_node
      
      return attr