Issue #2822382 by voleger, pfrenssen, erozqba, RytoEX, borisson_, sidharthap, Jo Fitzgerald, shashikant_chauhan: Make every  property protected on classes extending BrowserTestBase and KernelTestBase

(cherry picked from commit 69501f30)

Issue #2665992 by alexpott, klausi, heykarthikwithu, xjm, tstoeckler: @file is not required for classes, interfaces and traits

Issue #2594263 by phenaproxima, neclimdul, Gábor Hojtsy, Kazanir: Add translation data to Migrate Drupal's test fixtures

Issue #2557253 by phenaproxima, neclimdul: MigrateFullDrupalTestBase test discovery gobbles all the memory

Issue #2550823 by phenaproxima, neclimdul: Migrate Drupal integration tests should load all dump files

Issue #2258177 by amateescu, sun, mikeryan, bdone, dawehner, Berdir: Convert migrate_drupal tests to KernelTestBase

Issue #2340667 by YesCT, Pedro Lozano, alexpott, martin107: Protect Drupal\Core\Language\Language::id, and use getId().

Issue #2321501 by Temoor, prics: Replace calls to aggregator_feed_load(), entity_load('aggregator_feed') and entity_load_multiple() with static method calls.

Issue #1966436 by naveenvalecha, cesarmiquel, Berdir, mr.york, jlbellido, segi, vasi1186, Leksat, Gábor Hojtsy, Schnitzel, grisendo, Aron Novak, likin, penyaskito, vijaycs85, kfritsche, fago: Fixed Default *content* entity languages are not set for entities created with the API.

Issue #697760 by sun: Replace getInfo() in tests with native phpDoc + annotations (following PHPUnit).

Issue #2246665 by jaredsmith, martin107, YesCT, filijonka, tstoeckler: Typehint with Drupal\Core\Language\LanguageInterface instead Drupal\Core\Language\Language.

Issue #2248149 by jessebeach, donquixote, sun: Use __DIR__ instead of drupal_get_path() for local PSR-0/PSR-4 directories.

Issue #2121299 by andypost, bdone, benjy, penyaskito, chx, claudiu.cristea, damiankloip, gregboggs, InternetDevels, jessehs, jhedstrom, marvil07, mikeryan, pcambra, Xano, YesCT, axoplasm, kgoel, dclavain, jeckman, alvar0hurtad0, Drupali, fastangel, gloob, jhedstrom, joshtaylor, mpgeek, alexpott: Migrate Drupal 6 to Drupal 8