anchor.diff:              let snapped = Math.snap2F snap position
               this.SetPosition snapped world
   
  -        member this.GetTransform world =
  -            { Transform.Position = this.GetPosition world
  +        member this.GetTransform world : Transform =
  +            { Position = this.GetPosition world
                 Depth = this.GetDepth world
                 Size = this.GetSize world
                 Rotation = this.GetRotation world }
  
positive.code:             let dispatcher = entityRep.GetDispatcherNp world : EntityDispatcher
              dispatcher.GetPickingPriority entityRep world
  
          /// Get the names of all facets used by an entity via reflection.
          /// TODO: see if this should be used as often as it is, and if it is needed in only one or
          /// two cases, just inline it.
          static member getFacetNamesReflectively entity =
              List.map Reflection.getTypeName entity.FacetsNp
  
          /// Query that a facet is compatible with those already being used by an entity.
          /// Note a facet is incompatible with any other facet if it contains any fields that has
          /// the same name but a different type.
          static member isFacetCompatible entityDispatcherMap facet (entity : Entity) =
              let facetType = facet.GetType ()
              let facetFieldDefinitions = Reflection.getFieldDefinitions facetType
              if Reflection.isFacetCompatibleWithDispatcher entityDispatcherMap facet entity then
                  List.notExists
                      (fun definition ->
                          match Map.tryFind definition.FieldName entity.Xtension.XFields with
                          | Some field -> field.GetType () <> definition.FieldType
                          | None -> false)
                      facetFieldDefinitions
              else false
  
          /// Remove an entity from the world immediately. Can be dangerous if existing in-flight
          /// subscriptions depend on the entity's existence. Use with caution.
          static member removeEntityImmediate entityRep world =
  
negative.code:                 world
                  entities
  
          /// TODO: document!
          static member pickingSort entityReps world =
              let prioritiesAndEntityReps = List.map (fun (entityRep : EntityRep) -> (World.getPickingPriority entityRep world, entityRep)) entityReps
              let prioritiesAndEntityReps = List.sortWith World.sortFstDesc prioritiesAndEntityReps
              List.map snd prioritiesAndEntityReps
  
          /// TODO: document!
          static member tryPick position entityReps world =
              let entityRepsSorted = World.pickingSort entityReps world
              List.tryFind
  