'Test determination of the maximum depth beneath a node'

def testDepth(self):

    uids = self.uids
    rows = self.rows
    assertEqual = self.assertEqual
    h = S3Hierarchy('test_hierarchy')
    node = uids['HIERARCHY1']
    assertEqual(h.depth(node), 2)
    node = uids['HIERARCHY2-1']
    assertEqual(h.depth(node), 1)
    node = uids['HIERARCHY1-1-1']
    assertEqual(h.depth(node), 0)
    assertEqual(h.depth(None), 2)
