def add_node(self, klass):
        name = klass.__name__
        if not self.nodes.has_key(name):
            node = TreeNode(klass)
            self.nodes[name] = node
            return node
Construct an `AsynchronousDeferredRunTest`.
dataset/ETHPy150Open VisTrails/VisTrails/contrib/titan/class_tree.py/ClassTree.add_node--crossover with--dataset/ETHPy150Open byt3bl33d3r/pth-toolkit/lib/python2.7/site-packages/samba/external/testtools/deferredruntest.py/AsynchronousDeferredRunTest.__init__