* @param sourceTile a <code>Tile</code> value
     * @return a <code>JLabel</code> value
     */
    private JLabel enterUnitOutForAnimation(final Unit unit, final Tile sourceTile) {
        Integer i = unitsOutForAnimation.get(unit);
        if (i == null) {
            final JLabel unitLabel = getUnitLabel(unit);
            final Integer UNIT_LABEL_LAYER = JLayeredPane.DEFAULT_LAYER;

            i = 1;
            unitLabel.setLocation(getUnitLabelPositionInTile(unitLabel,
                    getTilePosition(sourceTile)));
            unitsOutForAnimationLabels.put(unit, unitLabel);
            gui.getCanvas().addToCanvas(unitLabel, UNIT_LABEL_LAYER);
        } else {
            i++;
        }
        unitsOutForAnimation.put(unit, i);
        return unitsOutForAnimationLabels.get(unit);
    }