public function testParseNullValueParameter()
 {
     $parameter = $this->parser->parse('foo');
     $this->assertEquals('foo', $parameter->getAttribute());
     $this->assertNull($parameter->getValue());
     $this->assertEquals('foo', (string) $parameter);
 }
 /**
  *
  * @return \webignition\InternetMediaType\Parameter\Parser\Parser 
  */
 private function getParameterParser()
 {
     if (is_null($this->parameterParser)) {
         $this->parameterParser = new ParameterParser();
         $this->parameterParser->setConfiguration($this->getConfiguration());
     }
     return $this->parameterParser;
 }