public function assertResponseHeader($name, $value)
{
$CI =& get_instance();
$actual = $CI->output->get_header($name);
if ($actual === null) {
$this->fail("The '{$name}' header is not set.\nNote that `assertResponseHeader()` can only assert headers set by `\$this->output->set_header()`");
}
$this->assertEquals($value, $actual, "The '{$name}' header is not '{$value}' but '{$actual}'.");
}