public final function contains( Rectangle $rect ) : bool
   {

      return (
         (
            (
               (
                  $this->point->x <= $rect->point->x
               )
               && (
                  ( $rect->point->x + $rect->size->width ) <= ( $this->point->x + $this->size->width )
               )
            )
            &&
            (
               $this->point->y <= $rect->point->y
            )
         )
         &&
         (
            ( $rect->point->y + $rect->size->height ) <= ( $this->point->y + $this->size->height )
         )
      );

   }