'Children of L{Node} instances must also be L{Node} instances.'

def test_validChildInstance(self):

    node = microdom.Node()
    child = microdom.Node()
    node.appendChild(child)
    self.assertRaises(TypeError, node.appendChild, None)
    self.assertRaises(TypeError, node.insertBefore, child, None)
    self.assertRaises(TypeError, node.insertBefore, None, child)
    self.assertRaises(TypeError, node.insertBefore, None, None)
    node.removeChild(child)
    self.assertRaises(TypeError, node.removeChild, None)
    self.assertRaises(TypeError, node.replaceChild, child, None)
    self.assertRaises(TypeError, node.replaceChild, None, child)
    self.assertRaises(TypeError, node.replaceChild, None, None)
