6 string references to language_negotiator in Drupal 9

ConfigurableLanguageManagerTest::setUp in core/modules/language/tests/src/Kernel/ConfigurableLanguageManagerTest.php

ConfigurableLanguageManagerTest::testUrlContentTranslationWithPreferredAdminLanguage in core/modules/language/tests/src/Functional/ConfigurableLanguageManagerTest.php

Tests translation with URL and Preferred Admin Language negotiators.

ConfigurableLanguageManagerTest::testUrlContentTranslationWithSessionLanguage in core/modules/language/tests/src/Functional/ConfigurableLanguageManagerTest.php

Tests translation with URL and Session Language Negotiators.

ConfigurableLanguageManagerTest::testUserProfileTranslationWithPreferredAdminLanguage in core/modules/language/tests/src/Functional/ConfigurableLanguageManagerTest.php

Tests translation of the user profile edit form.

language_modules_installed in core/modules/language/language.module

Implements hook_modules_installed().

NegotiationConfigureForm::create in core/modules/language/src/Form/NegotiationConfigureForm.php

Instantiates a new instance of this class.