Piwik\Plugin\Manager::deactivatePlugin PHP Method

    public function deactivatePlugin($pluginName)
    {
        $this->clearCache($pluginName);
        // execute deactivate() to let the plugin do cleanups
        $this->executePluginDeactivate($pluginName);
        $this->unloadPluginFromMemory($pluginName);
        $this->removePluginFromConfig($pluginName);
        /**
         * Event triggered after a plugin has been deactivated.
         *
         * @param string $pluginName The plugin that has been deactivated.
         */
        Piwik::postEvent('PluginManager.pluginDeactivated', array($pluginName));
    }

 public function test_deactivatePlugin()
 {
     $this->assertFalse($this->manager->isPluginActivated('ExampleTheme'));
     $this->manager->activatePlugin('ExampleTheme');
     $this->assertTrue($this->manager->isPluginActivated('ExampleTheme'));
     $this->manager->deactivatePlugin('ExampleTheme');
     $this->assertFalse($this->manager->isPluginActivated('ExampleTheme'));
 }