function assertEmailMismatchPage(userEmail, pendingEmail) {
  // Constructed expected title message.
  var titleMessage = 'Continue with ' + userEmail + '?';
  // Asserts that email mismatch page is displayed.
  assertPage_(container, 'firebaseui-id-page-email-mismatch');
  // Ensures the correct subtitle and text are displayed.
  var element = goog.dom.getElementByClass('firebaseui-subtitle', container);
  assertContains(titleMessage, goog.dom.getTextContent(element));
  assertPageContainsText(pendingEmail);
}
Asserts that the email mismatch page is displayed with the corresponding
user email and pending email.
@param {string} userEmail The idp returned email to verify.
@param {string} pendingEmail The pending email to verify.