Piwik\Plugin\Manager::unloadPlugin PHP Method

    public function unloadPlugin($plugin)
    {
        $this->resetTransientCache();
        if (!$plugin instanceof Plugin) {
            $oPlugin = $this->loadPlugin($plugin);
            if ($oPlugin === null) {
                unset($this->loadedPlugins[$plugin]);
                return;
            }
            $plugin = $oPlugin;
        }
        unset($this->loadedPlugins[$plugin->getPluginName()]);
    }