Check to see if two values are identical.
$first: The first value to check.
$second: The second value to check.
$message: The message to display along with the assertion.
$group: The type of assertion - examples are "Browser", "PHP".
TRUE if the assertion succeeded, FALSE otherwise.
protected function assertIdentical($first, $second, $message = '', $group = 'Other') {
  return $this
    ->assert($first === $second, $message ? $message : t('Value @first is identical to value @second.', array(
    '@first' => var_export($first, TRUE),
    '@second' => var_export($second, TRUE),
  )), $group);
}