| @@ -87,6 +87,6 @@ | ||
| 87 | 87 | */ | 
| 88 | 88 | public function __toString(): string | 
| 89 | 89 |      { | 
| 90 | -        return "(" . $this->sourceVertex + " : " + $this->targetVertex + ")"; | |
| 90 | +        return "(" . $this->sourceVertex + " : " +$this->targetVertex + ")"; | |
| 91 | 91 | } | 
| 92 | 92 | } |