public function add($name, $dependencyUnit, $arguments = array()) {
        if (is_object($dependencyUnit)) {
            $dependencyClass = get_class($dependencyUnit);
        } else {
            $dependencyClass = $dependencyUnit;
        }
        if (!is_array($arguments)) $arguments = array('arguments' => $arguments);

        $this->_dependencies[$name] = array_merge($arguments, array(
            'className' => $dependencyClass,
            'object'    => !empty($arguments['object']) ? $arguments['object'] : null
        ));
    }