'Compute the max depth for the given part of speech.  This is
used by the lch similarity metric.'

def _compute_max_depth(self, pos, simulate_root):

    depth = 0
    for ii in self.all_synsets(pos):
        try:
            depth = max(depth, ii.max_depth())
        except RuntimeError:
            print(ii)
    if simulate_root:
        depth += 1
    self._max_depth[pos] = depth
