Ouzo\Utilities\Strings::appendIfMissing PHP Method

    public static function appendIfMissing($string, $suffix)
    {
        if (Strings::endsWith($string, $suffix)) {
            return $string;
        }
        return Strings::appendSuffix($string, $suffix);
    }

 /**
  * @test
  */
 public function shouldAppendSuffixIfNecessary()
 {
     // when
     $modified = Strings::appendIfMissing('You know nothing, Jon Snow', ', Jon Snow');
     $original = Strings::appendIfMissing('You know nothing', ', Jon Snow');
     // then
     $this->assertEquals($original, 'You know nothing, Jon Snow');
     $this->assertEquals($modified, 'You know nothing, Jon Snow');
 }