Undefined variable $terms in TaxonomyIndexTidUiTest

Problem/Motivation

Undefined variable $terms in core/modules/taxonomy/tests/src/Functional/Views/TaxonomyIndexTidUiTest.php

for ($i = 0; $i < 3; $i++) {
  for ($j = 0; $j <= $i; $j++) {
    $this->terms[$i][$j] = $term = Term::create([
      'vid' => 'tags',
      'name' => "Term $i.$j",
      'parent' => isset($terms[$i][0]) ? $terms[$i][0]->id() : 0,
    ]);
    $term->save();
  }
}

Proposed resolution

--- a/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyIndexTidUiTest.php
+++ b/core/modules/taxonomy/tests/src/Functional/Views/TaxonomyIndexTidUiTest.php
@@ -71,7 +71,7 @@ protected function setUp($import_test_views = TRUE) {
         $this->terms[$i][$j] = $term = Term::create([
           'vid' => 'tags',
           'name' => "Term $i.$j",
-          'parent' => isset($terms[$i][0]) ? $terms[$i][0]->id() : 0,
+          'parent' => isset($this->terms[$i][0]) ? $this->terms[$i][0]->id() : 0,