anchor.diff:                  ValueNone
   
   /// TexturePacking represents an immutable 2D atlas.
  -type TexturePacking<'a when 'a : equality> private(atlasSize : V2i, free : BvhTree2d<Box2i, Box2i>, used : HashMap<'a, Box2i>) =
  +type TexturePacking<'a when 'a : equality> private(atlasSize : V2i, allowRotate : bool, free : BvhTree2d<Box2i, Box2i>, used : HashMap<'a, Box2i>) =
   
       let validate() =
           
  
positive.code:                 (free, merge rect adjacent)
                  ||> Seq.fold (fun free a -> addFree a free)
                  
              TexturePacking(atlasSize, free, used)
          | ValueNone ->
              x
  
  
negative.code:                         )
  
                      let result =
                          TexturePacking(atlasSize, allowRotate, free, HashMap.add id rect used)
  
                      Some result
                  | ValueNone ->
  