public function testEmptyValue($expectedValue, $serializedType)
{
$xml = sprintf('<?xml version="1.0" encoding="UTF-8"?>
<methodResponse>
<params>
<param>
<value>
<%s/>
</value>
</param>
</params>
</methodResponse>', $serializedType);
$this->assertEquals(null, $this->parser->parse($xml));
}