public function testSetPluginSelectLanguageColumns() {
        $this->MainOption->setPluginSelectLanguageColumns('abc');
        $this->assertEquals('abc', $this->MainOption->getPluginSelectLanguageColumns());
        $this->MainOption->setPluginSelectLanguageColumns(['_' => 'abc']);
        $this->assertEquals(['_' => 'abc'], $this->MainOption->getPluginSelectLanguageColumns());