'Return a python list containing the statistics about the node tree:
0: number of nodes (tree size)
1: number of unique nodes
2: number of trapezoids (tree leaf nodes)
3: number of unique trapezoids
4: maximum parent count (max number of times a node is repeated in
tree)
5: maximum depth of tree (one more than the maximum number of
comparisons needed to search through the tree)
6: mean of all trapezoid depths (one more than the average number
of comparisons needed to search through the tree)'

def _get_tree_stats(self):

    return self._cpp_trifinder.get_tree_stats()
