@Test
public void export() {

  exporter = new CsvExporter(2, "foo", "bar");
  assertEquals("foo,bar\n", exporter.export());
  exporter.addRow("hello", "world");
  assertEquals("foo,bar\nhello,world\n", exporter.export());
  exporter.clear();
  assertEquals("foo,bar\n", exporter.export());
}