function test_export_headers()
{
$po = new PO();
$po->set_header('Project-Id-Version', 'WordPress 2.6-bleeding');
$po->set_header('POT-Creation-Date', '2008-04-08 18:00+0000');
$this->assertEquals("msgid \"\"\nmsgstr \"\"\n\"Project-Id-Version: WordPress 2.6-bleeding\\n\"\n\"POT-Creation-Date: 2008-04-08 18:00+0000\\n\"", $po->export_headers());
}