Test title callback set to FALSE.
function testTitleCallbackFalse() {
$this
->drupalGet('test-page');
$this
->assertText('A title with @placeholder', 'Raw text found on the page');
$this
->assertNoText(t('A title with @placeholder', array(
'@placeholder' => 'some other text',
)), 'Text with placeholder substitutions not found.');
}