public FieldArea[] getFieldAreas() {
		int n = getNumberOfInstances(FieldArea.class);
		if (n == 0)
			return null;
		FieldArea[] fa = new FieldArea[n];
		n = 0;
		synchronized (layerBasket) {
			for (Layered c : layerBasket) {
				if (c instanceof FieldArea)
					fa[n++] = (FieldArea) c;
			}
		}
		return fa;
	}