code: public function translate($shift, $y = null, $z = null)
    {
      if($shift instanceof self)
        return new static($this->gps['x'] + $shift->gps['x'], $this->gps['y'] + $shift->gps['y'], $this->gps['z'] + $shift->gps['z']);
      else
        return new static($this->gps['x'] + $shift, $this->gps['y'] + $y, $this->gps['z'] + $z);
    }
docs: Translate coordinate in space
  
  @param Coordinate3D|int $shift|$x the distances by which a coordinate must be translated.
  @param ?int $y the distances by which a coordinate must be translated.
  @param ?int $z the distances by which a coordinate must be translated.
  @return Coordinate3D the translated coordinate