getTileAbove gives error but getTile does not

[microspace]

I create layer from Tiled with these commands:

var map;
var fog;
var flour;
...
map = this.game.add.tilemap('lesson51');
map.addTilesetImage('tileSheetWinter', 'gameTiles');
flour = map.createLayer('flour');
fog = map.createLayer('fog');
flour.resizeWorld();
...

Why `map.getTileAbove(fog, x, y);` gives error TypeError: Cannot read property 'data' of undefined

but map.getTile(x, y, fog); return Tile object as expected?

[samme]

https://photonstorm.github.io/phaser-ce/Phaser.Tilemap.html#getTileAbove

[microspace]

Sorry, I didnt notice that I removed reference tile, thats why error occured