diff --git a/core/modules/migrate/src/Source.php b/core/modules/migrate/src/Source.php
index 63a5051..473f46f 100644
--- a/core/modules/migrate/src/Source.php
+++ b/core/modules/migrate/src/Source.php
@@ -167,7 +167,7 @@ public function __construct(MigrationInterface $migration, MigrateExecutable $mi
 
     // Don't allow the use of both highwater and track changes together.
     if ($this->highWaterProperty && $this->trackChanges) {
-      throw new MigrateException($this->t('You should either use a highwater mark or track changes not both. They are both designed to solve the same problem'));
+      throw new MigrateException('You should either use a highwater mark or track changes not both. They are both designed to solve the same problem');
     }
   }
 
@@ -428,27 +428,4 @@ protected function prepareRow(Row $row) {
     return $result;
   }
 
-  /**
-   * Translate the string.
-   *
-   * @param string $string
-   *   A string containing the English string to translate.
-   * @param array $args
-   *   (optional) An associative array of replacements to make after translation. Based
-   *   on the first character of the key, the value is escaped and/or themed.
-   *   See format_string() for details.
-   * @param array $options
-   *   (optional) An associative array of additional options, with the following elements:
-   *   - 'langcode' (defaults to the current language): The language code to
-   *     translate to a language other than what is used to display the page.
-   *   - 'context' (defaults to the empty context): The context the source string
-   *     belongs to.
-   *
-   * @return string
-   *   The translated string.
-   */
-  protected function t($string, array $args = array(), array $options = array()) {
-    return \Drupal::translation()->translate($string, $args, $options);
-  }
-
 }
diff --git a/core/modules/migrate/tests/src/Unit/MigrateSourceTest.php b/core/modules/migrate/tests/src/Unit/MigrateSourceTest.php
index 91e8057..2158a35 100644
--- a/core/modules/migrate/tests/src/Unit/MigrateSourceTest.php
+++ b/core/modules/migrate/tests/src/Unit/MigrateSourceTest.php
@@ -7,9 +7,10 @@
 
 namespace Drupal\Tests\migrate\Unit;
 
+use Drupal\Core\DependencyInjection\ContainerBuilder;
 use Drupal\migrate\MigrateExecutable;
 use Drupal\migrate\Plugin\MigrateIdMapInterface;
-use Drupal\migrate\TestSource;
+use Drupal\migrate\Source;
 
 /**
  * @coversDefaultClass \Drupal\migrate\Source
@@ -70,14 +71,14 @@ public function setUp() {
   public function testHighwaterTrackChangesIncompatible() {
     $this->migration->set('source', ['track_changes' => TRUE]);
     $this->migration->set('highWaterProperty', ['name' => 'something']);
-    new TestSource($this->migration, $this->executable);
+    new Source($this->migration, $this->executable);
   }
 
   /**
    * Test that $row->needsUpdate() works as expected.
    */
   public function testNextNeedsUpdate() {
-    $source = new TestSource($this->migration, $this->executable);
+    $source = new Source($this->migration, $this->executable);
 
     // $row->needsUpdate() === TRUE so we get a row.
     $source->rewind();
@@ -98,7 +99,7 @@ public function testOutdatedHighwater() {
     // been imported. This allows us to use the highwater mark to decide on the
     // outcome of whether we choose to import the row.
     $this->changeDefaultRowStatus(MigrateIdMapInterface::STATUS_IMPORTED);
-    $source = new TestSource($this->migration, $this->executable);
+    $source = new Source($this->migration, $this->executable);
 
     // Set the originalHighwater to something higher than our timestamp.
     $this->migration
@@ -126,7 +127,7 @@ public function testNewHighwater() {
     // Set a highwater property field for source. Now we should have a row
     // because the row timestamp is greater than the current highwater mark.
     $this->migration->set('highWaterProperty', ['name' => 'timestamp']);
-    $source = new TestSource($this->migration, $this->executable);
+    $source = new Source($this->migration, $this->executable);
 
     $source->rewind();
     $this->assertTrue(is_a($source->current(), 'Drupal\migrate\Row'), 'Incoming row timestamp is greater than current highwater mark so we have a row.');
@@ -196,11 +197,3 @@ protected function changeDefaultRowStatus($status) {
   }
 
 }
-
-namespace Drupal\migrate;
-
-class TestSource extends Source {
-  protected function t($string, array $args = array(), array $options = array()) {
-    return $string;
-  }
-}