public function removeCallback($name, $callback, $prio = 10)
    {
        $key = $this->getCallbackKey($callback);

        if (in_array($key, $this->_callbacks[$name][$prio])) {
            while(false !== $k = array_search($key, $this->_callbacks[$name][$prio])) {
                unset($this->_callbacks[$name][$prio][$k]);
            }
            if (empty($this->_callbacks[$name][$prio])) {
                unset($this->_callbacks[$name][$prio]);
            }
            if (empty($this->_callbacks[$name])) {
                unset($this->_callbacks[$name]);
            }
        }

        return $this;       
    }