function diagnostics_test_test()
{
    ob_start();
    for ($n = 0; $n < 5; $n++) {
        echo "{$n} ";
    }
    return ElggTestResult::CreateSuccessResult(ob_get_clean());
}
<?php

/**
 * Elgg diagnostics - test report
 * 
 * @package ElggDiagnostics
 * @author Curverider Ltd
 * @link http://elgg.com/
 */
$result = $vars['result'];
$testresult_div = 'fail';
$successmessage = "";
if (!$result instanceof ElggTestResult) {
    $successmessage = elgg_echo('diagnostics:unittester:testresult:nottestclass');
    $result = ElggTestResult::CreateFailResult(elgg_echo('diagnostics:unittester:testresult:fail'));
} else {
    if ($result->isSuccess()) {
        $successmessage = elgg_echo('diagnostics:unittester:testresult:success');
    } else {
        $successmessage = elgg_echo('diagnostics:unittester:testresult:fail');
    }
}
?>
<div class="testreport">
	<div class="testreport_<?php 
echo $testresult_div;
?>
">
		<div class="testreport_header">
			<p><b><?php 
echo $vars['function'];