   }
 }
 
-protocol PointsContainter {
+protocol PointsContainer {
   func add(point: Point) -> Bool
   func points(inRect rect: Rect) -> [Point]
 }

  }
}

extension QuadTreeNode: PointsContainter {
  
  @discardableResult
  func add(point: Point) -> Bool {

  }
}

public class QuadTree: PointsContainer {
  
  let root: QuadTreeNode
  
