public function testInvalidDataFormat()
{
$writer = new XmlWriter($this->filename);
$writer->open();
$writer->write(array('firstname' => 'john 1', 'lastname' => 'doe', 'id' => '1'));
$writer->write(array('firstname' => 'john 3', 'lastname' => 'doe', 'id' => '1'));
$writer->close();
$expected = <<<'XML'
<?xml version="1.0" ?>
<datas>
<data>
<firstname><![CDATA[john 1]]></firstname>
<lastname><![CDATA[doe]]></lastname>
<id><![CDATA[1]]></id>
</data>
<data>
<firstname><![CDATA[john 3]]></firstname>
<lastname><![CDATA[doe]]></lastname>
<id><![CDATA[1]]></id>
</data>
</datas>
XML;
$this->assertEquals($expected, file_get_contents($this->filename));
}