public function testGetNamespacePrelude()
 {
     $this->assertType('string', MwRdf::getNamespacePrelude());
     $parser = new LibRDF_Parser('turtle');
     $i = $parser->parseString(MwRdf::getNamespacePrelude());
     $this->assertTrue($i instanceof LibRDF_StreamIterator, get_class($i));
     // this should be a completely empty result, we're just proving it
     // can be parsed
     $this->assertNull($i->current());
     $this->assertNull($i->next());
 }