diff --git a/core/tests/Drupal/FunctionalTests/AssertLegacyTrait.php b/core/tests/Drupal/FunctionalTests/AssertLegacyTrait.php
index c57bc94..ebd4850 100644
--- a/core/tests/Drupal/FunctionalTests/AssertLegacyTrait.php
+++ b/core/tests/Drupal/FunctionalTests/AssertLegacyTrait.php
@@ -148,6 +148,32 @@ protected function assertFieldById($id, $value = NULL) {
   }
 
   /**
+   * Asserts that a field exists with the given name or ID.
+   *
+   * @param string $field
+   *   Name or ID of field to assert.
+   *
+   * @deprecated Scheduled for removal in Drupal 9.0.0.
+   *   Use $this->assertSession()->fieldExists() instead.
+   */
+  protected function assertField($field) {
+    $this->assertSession()->fieldExists($field);
+  }
+
+  /**
+   * Asserts that a field exists with the given name or ID does NOT exist.
+   *
+   * @param string $field
+   *   Name or ID of field to assert.
+   *
+   * @deprecated Scheduled for removal in Drupal 9.0.0.
+   *   Use $this->assertSession()->fieldNotExists() instead.
+   */
+  protected function assertNoField($field) {
+    $this->assertSession()->fieldNotExists($field);
+  }
+
+  /**
    * Passes if the raw text IS found on the loaded page, fail otherwise.
    *
    * Raw text refers to the raw HTML that the page generated.
@@ -182,8 +208,13 @@ protected function assertNoRaw($raw) {
    *
    * @param string $expected_title
    *   The string the page title should be.
+   *
+   * @deprecated Scheduled for removal in Drupal 9.0.0.
+   *   Use $this->assertSession()->titleEquals() instead.
    */
   protected function assertTitle($expected_title) {
+    // Cast MarkupInterface to string.
+    $expected_title = (string) $expected_title;
     return $this->assertSession()->titleEquals($expected_title);
   }
 
@@ -343,6 +374,19 @@ protected function assertNoEscaped($raw) {
   }
 
   /**
+   * Asserts whether an expected cache tag was present in the last response.
+   *
+   * @param string $expected_cache_tag
+   *   The expected cache tag.
+   *
+   * @deprecated Scheduled for removal in Drupal 9.0.0.
+   *   Use $this->assertSession()->responseHeaderContains() instead.
+   */
+  protected function assertCacheTag($expected_cache_tag) {
+    $this->assertSession()->responseHeaderContains('X-Drupal-Cache-Tags', $expected_cache_tag);
+  }
+
+  /**
    * Returns WebAssert object.
    *
    * @param string $name
@@ -353,4 +397,31 @@ protected function assertNoEscaped($raw) {
    */
   abstract public function assertSession($name = NULL);
 
+  /**
+   * Builds an XPath query.
+   *
+   * Builds an XPath query by replacing placeholders in the query by the value
+   * of the arguments.
+   *
+   * XPath 1.0 (the version supported by libxml2, the underlying XML library
+   * used by PHP) doesn't support any form of quotation. This function
+   * simplifies the building of XPath expression.
+   *
+   * @param string $xpath
+   *   An XPath query, possibly with placeholders in the form ':name'.
+   * @param array $args
+   *   An array of arguments with keys in the form ':name' matching the
+   *   placeholders in the query. The values may be either strings or numeric
+   *   values.
+   *
+   * @return string
+   *   An XPath query with arguments replaced.
+   *
+   * @deprecated Scheduled for removal in Drupal 9.0.0.
+   *   Use $this->assertSession()->buildXPathQuery() instead.
+   */
+  public function buildXPathQuery($xpath, array $args = array()) {
+    return $this->assertSession()->buildXPathQuery($xpath, $args);
+  }
+
 }
diff --git a/core/tests/Drupal/Tests/BrowserTestBase.php b/core/tests/Drupal/Tests/BrowserTestBase.php
index f22cbc8..bef34ab 100644
--- a/core/tests/Drupal/Tests/BrowserTestBase.php
+++ b/core/tests/Drupal/Tests/BrowserTestBase.php
@@ -48,6 +48,7 @@
   use RandomGeneratorTrait;
   use SessionTestTrait;
   use NodeCreationTrait {
+    getNodeByTitle as drupalGetNodeByTitle;
     createNode as drupalCreateNode;
   }
   use ContentTypeCreationTrait {
diff --git a/core/tests/Drupal/Tests/WebAssert.php b/core/tests/Drupal/Tests/WebAssert.php
index c0744a8..6156dda 100644
--- a/core/tests/Drupal/Tests/WebAssert.php
+++ b/core/tests/Drupal/Tests/WebAssert.php
@@ -80,6 +80,24 @@ public function buttonExists($button, TraversableElement $container = NULL) {
   }
 
   /**
+   * Checks that the specific button does NOT exist on the current page.
+   *
+   * @param string $button
+   *   One of id|name|label|value for the button.
+   * @param \Behat\Mink\Element\TraversableElement $container
+   *   (optional) The document to check against. Defaults to the current page.
+   *
+   * @throws \Behat\Mink\Exception\ExpectationException
+   *   When the button exists.
+   */
+  public function buttonNotExists($button, TraversableElement $container = NULL) {
+    $container = $container ?: $this->session->getPage();
+    $node = $container->findButton($button);
+
+    $this->assert(NULL === $node, sprintf('A button "%s" appears on this page, but it should not.', $button));
+  }
+
+  /**
    * Checks that specific select field exists on the current page.
    *
    * @param string $select
@@ -375,4 +393,33 @@ public function assert($condition, $message) {
     throw new ExpectationException($message, $this->session->getDriver());
   }
 
+  /**
+   * Checks that a given form field element is disabled.
+   *
+   * @param string $field
+   *   One of id|name|label|value for the field.
+   * @param \Behat\Mink\Element\TraversableElement $container
+   *   (optional) The document to check against. Defaults to the current page.
+   *
+   * @return \Behat\Mink\Element\NodeElement
+   *   The matching element.
+   *
+   * @throws \Behat\Mink\Exception\ElementNotFoundException
+   * @throws \Behat\Mink\Exception\ExpectationException
+   */
+  public function fieldDisabled($field, TraversableElement $container = NULL)  {
+    $container = $container ?: $this->session->getPage();
+    $node = $container->findField($field);
+
+    if ($node === NULL) {
+      throw new ElementNotFoundException($this->session->getDriver(), 'field', 'id|name|label|value', $field);
+    }
+
+    if (!$node->hasAttribute('disabled')) {
+      throw new ExpectationException("Field $field is disabled", $this->session->getDriver());
+    }
+
+    return $node;
+  }
+
 }