Python give_chain_link_pairs() — efficient loopback iterator!

from typing import TypeVar, Iterable, Iterator, Tuple
from more_itertools import spy
from itertools import chain, pairwise


_T = TypeVar('_T')


def give_chain_link_pairs(links: Iterable[_T], cycle_preview: int = 1) -> Iterator[Tuple[_T]]:
    first_values, new_iterator = spy(iter(links), n = cycle_preview)
    yield from pairwise(chain(new_iterator, reversed(first_values)))  # loopback