def extend_paginator(cls, page_items: Page):
"""Дополняет объект постраничной навигации.
:param page_items:
"""
max_pages_before_after = 10
page = page_items.number
min_page_before = page - max_pages_before_after
if min_page_before < 1:
min_page_before = 0
max_page_after = page + max_pages_before_after
if max_page_after > page_items.paginator.num_pages:
max_page_after = page_items.paginator.num_pages
page_items.before_current = reversed(
range(page - 1, min_page_before, -1))
page_items.after_current = range(page + 1, max_page_after + 1)
