def get_tip_labels(self, idx=None):
if not idx:<EOL><INDENT>return self.treenode.get_leaf_names()[::-<NUM_LIT:1>]<EOL><DEDENT>else:<EOL><INDENT>treenode = self.treenode.search_nodes(idx=idx)[<NUM_LIT:0>]<EOL>return treenode.get_leaf_names()[::-<NUM_LIT:1>]<EOL><DEDENT>
Returns tip labels in the order they will be plotted on the tree, i.e.,
starting from zero axis and counting up by units of 1 (bottom to top 
in right-facing trees; left to right in down-facing). If 'idx' is 
indicated then a list of tip labels descended from that node will be 
returned, instead of all tip labels. This is useful in combination 
with other functions that select nodes/clades of the tree based on a 
list of tip labels. You can use the toytree draw() command with 
tip_labels='idx' or tip_labels=True to see idx labels plotted on nodes. 

Parameters:
    idx (int): index label of a node.

Example:
    # select a clade of the tree and use it for rooting.
    tiplist = tre.get_descenants_from_idx(21)
    tre.root(names=tiplist)