public function renderSetsTagContentToEmailIfRenderChildrenReturnNull()
{
$mockTagBuilder = $this->createMock(\TYPO3Fluid\Fluid\Core\ViewHelper\TagBuilder::class);
$mockTagBuilder->expects($this->once())->method('setContent')->with('[email protected]');
$this->viewHelper->injectTagBuilder($mockTagBuilder);
$this->viewHelper->expects($this->any())->method('renderChildren')->will($this->returnValue(null));
$this->viewHelper->initialize();
$this->viewHelper->render('[email protected]');
}