@property
    def next_sibling(self):
        """
        The node immediately following the invocant in their parent's children
        list. If the invocant does not have a next sibling, it is None
        """
        if self.parent is None:
            return None

        # Can't use index(); we need to test by identity
        for i, child in enumerate(self.parent.children):
            if child is self:
                try:
                    return self.parent.children[i+1]
                except __HOLE__:
                    return None
dataset/ETHPy150Open ctxis/canape/CANAPE.Scripting/Lib/lib2to3/pytree.py/Base.next_sibling