public function testWriteWorkbook()
{
$file = new File('/tmp/test.xls');
$workbook = new Workbook();
$worksheet = $workbook->addWorksheet('My first worksheet');
$worksheet->write(0, 0, 'Name');
$worksheet->write(0, 1, 'Age');
$worksheet->write(1, 0, 'John Smith');
$worksheet->write(1, 1, 30);
$worksheet->write(2, 0, 'Johann Schmidt');
$worksheet->write(2, 1, 31);
$worksheet->write(3, 0, 'Juan Herrera');
$worksheet->write(3, 1, 32);
$workbook->write($file);
$exists = $file->exists();
$file->delete();
$this->assertTrue($exists, 'file was not saved');
}
