def completeTreeNames(tree, useBS = False ) :
    """
    Takes:
        - tree (ete3.Tree)
        - useBS (bool) [default = False] : uses bootstrap to name nodes

    Returns:
        (ete3.Tree) : the tree, but where the nodes without a name now have one that correspond
                    to their post-order OR their bootstrap

    """

    for i,n in enumerate(tree.traverse('postorder')):
        if n.name == "":
            print (n.support)
            if useBS:
                n.name = str(int(n.support))
            else:
                n.name = str(i)
    return tree