Callable test as proposed by @carlalexander

callables.php

<?php

/**
 * Callables executable test.
 *
 * @link https://github.com/semperfiwebdesign/all-in-one-seo-pack/issues/403
 * @author Alejandro Mostajo <@amostajo>
 */

/**
 * Text class with public and static classes.
 */
class Test
{
    protected $value = '@carlalexander';

    public function non_static()
    {
        return $this->value;
    }

    public static function with_static()
    {
        return '@amostajo';
    }
}

/**
 * Class instance.
 */
$test = new Test;

/**
 * Run callables. 
 * @link http://php.net/manual/en/language.types.callable.php
 */
try {

    ?><h1>Simple callback test</h1><?php

    // Type 2: Static class method call
    if ( call_user_func(array('Test', 'with_static')) === '@amostajo' ) {
        ?>
        <h2>Type 2: Static class method call</h2>
        <p>Sucess!</p>
        <?php
    }
    
    // Type 3: Object method call
    if ( call_user_func(array($test, 'non_static')) === '@carlalexander' ) {
        ?>
        <h2>Type 3: Object method call</h2>
        <p>Sucess!</p>
        <?php
    }
    
    // Type 4: Static class method call (As of PHP 5.2.3)
    if ( call_user_func('Test::with_static') === '@amostajo' ) {
        ?>
        <h2>Type 4: Static class method call (As of PHP 5.2.3)</h2>
        <p>Sucess!</p>
        <?php
    }
    
    // Type 5: Propesed by @carlalexander
    if ( call_user_func('Test::non_static') === '@carlalexander' ) {
        ?>
        <h2>Type 5: Propesed by @carlalexander</h2>
        <p>Sucess!</p>
        <?php
    }

} catch (Exception $e) {
    ?>
    <h1>Exception</h1>
    <pre>
        <?php print_r($e) ?>
    </pre>
    <?php
}