private void setAngleStep(final double STEP) {
        if (null == angleStep) {
            _angleStep = STEP;
        } else {
            if (!angleStep.isBound()) {
                angleStep.set(STEP);
            }
        }
    }
Private method that will be used to set the angleStep

@param STEP
src/main/java/eu/hansolo/tilesfx/Tile.java