def test_node_search():
n1 = Node("Node1")
n2 = Node("Node2")
n3 = Node("Node3")
n4 = Node("Node4")
n1.add_child(n2)
n1.add_child(n3)
n2.add_child(n4)
assert (None != n1.search("Node2"))
assert (None != n1.search("Node3"))
assert (None != n1.search("Node4"))
assert (None == n1.search("Node42"))
assert (None != n2.search("Node4"))
assert (None == n2.search("Node3"))
assert (None == n3.search("Node1"))
assert (None == n3.search("Node2"))
assert (None == n3.search("Node4"))
assert (None == n4.search("Node1"))
assert (None == n4.search("Node2"))
assert (None == n4.search("Node3"))
assert (None != n4.search("Node4"))
