swift - NSOutlineView leaks memory. What to do? -

when minimal osx application has nothing else plain (unconfigured) nsoutlineview in storyboard, heavily leak memory.

view controller implementation

the view controller implemented following:

import cocoa  class section {     let title: string     let items: [string]      init(title: string, items: [string]) {         self.title = title         self.items = items     } }  class viewcontroller: nsviewcontroller, nsoutlineviewdatasource, nsoutlineviewdelegate {      //mark: nsoutlineviewdatasource      let items = [         section(title: "alpha", items: ["anton",  "anita"]),         section(title: "beta",  items: ["bernd",  "barbara"]),         section(title: "gamma", items: ["gustav", "gesine"])]      func outlineview(outlineview: nsoutlineview, numberofchildrenofitem item: anyobject?) -> int {         switch item {         case nil:        return items.count         case section: return (item as! section).items.count         default:         return 0         }     }      func outlineview(outlineview: nsoutlineview, child index: int, ofitem item: anyobject?) -> anyobject {         return item == nil             ? items[index]             : (item as! section).items[index]     }      func outlineview(outlineview: nsoutlineview, isitemexpandable item: anyobject) -> bool {         return item section     }      func outlineview(outlineview: nsoutlineview, objectvaluefortablecolumn tablecolumn: nstablecolumn?, byitem item: anyobject?) -> anyobject? {         return item     }      //mark: nsoutlineviewdelegate      func outlineview(outlineview: nsoutlineview, viewfortablecolumn tablecolumn: nstablecolumn?, item: anyobject) -> nsview? {         let view = outlineview.makeviewwithidentifier(item section ? "headercell" : "datacell", owner: self) as! nstablecellview         view.textfield?.stringvalue = item section             ? (item as! section).title             : item as! string         return view     } } 

the xcode project can cloned github

xcode showing increasing memory consumption

when app started , tree items selected clicking them, memory consumption increases tremendously.

xcode's debug navigator shows increasing memory consumption on short time. memory increases when navigate through nsoutlineview nodes.

instruments not showing suspicious (or it?)

instruments showing constant memory usage, neither increasing nor decreasing:

what can conclude instrument's report? not detecting leaks because it's nsoutlineview leaking (and can't detected?) or there no leak @ end?