retype.py
def new(n, prefix=None):
    """lib2to3's AST requires unique objects as children."""

    if isinstance(n, Leaf):
        return Leaf(n.type, n.value, prefix=n.prefix if prefix is None else prefix)

    # this is hacky, we assume complex nodes are just being reused once from the
    # original AST.
    n.parent = None
    if prefix is not None:
        n.prefix = prefix
    return n
def new(n, prefix=None):
    """lib2to3's AST requires unique objects as children."""

    if isinstance(n, Leaf):
        return Leaf(n.type, n.value, prefix=n.prefix if prefix is None else prefix)

    # this is hacky, we assume complex nodes are just being reused once from the
    # original AST.
    n.parent = None
    if prefix is not None:
        n.prefix = prefix
    return n
lib2to3's AST requires unique objects as children.