def test_remove(self):
"""
Test removal of nodes.
"""
tree = Tree()
n1 = 'n1'
n2 = 'n2'
n3 = 'n3'
n4 = 'n4'
n5 = 'n5'
tree.add(n1)
tree.add(n2)
tree.add(n3, parent=n1)
tree.add(n4, parent=n3)
tree.add(n5, parent=n4)
assert tree._nodes == [n1, n3, n4, n5, n2]
all_ch = list(tree.get_all_children(n1))
assert all_ch == [ n3, n4, n5 ], all_ch
tree.remove(n4)
assert tree._nodes == [n1, n3, n2]
tree.remove(n1)
assert len(tree._children) == 2
assert tree._children[None] == [n2]
assert tree._children[n2] == []
assert tree._nodes == [n2]
