GetOptionKit\Option::valueName PHP Method

    public function valueName($name)
    {
        $this->valueName = $name;
        return $this;
    }

 public function testValueName()
 {
     $opt = new Option('z');
     $opt->defaultValue(10);
     $opt->valueName('priority');
     $this->assertEquals('[=priority]', $opt->renderValueHint());
     $this->assertEquals('-z[=priority]', $opt->renderReadableSpec());
 }