Change record status: 
Project: 
Introduced in branch: 
10.1.x
Introduced in version: 
10.1.0
Description: 

Before:

<?php
public function getCssAssets(AttachedAssetsInterface $assets, $optimize);
public function getJsAssets(AttachedAssetsInterface $assets, $optimize);

After:

<?php
use Drupal\Core\Language\LanguageInterface;

public function getCssAssets(AttachedAssetsInterface $assets, $optimize, LanguageInterface $language = NULL);
public function getJsAssets(AttachedAssetsInterface $assets, $optimize, LanguageInterface $language = NULL);
Impacts: 
Module developers