@Test
public void lengthProperty() {

	Vector2dfx vector = new Vector2dfx(1, 2);
	assertEpsilonEquals(2.23607, vector.getLength());
	
	ReadOnlyDoubleProperty property = vector.lengthProperty();
	assertNotNull(property);
	assertEpsilonEquals(2.23607, property.get());
	
	vector.set(4, -10);
	assertEpsilonEquals(10.77033, property.get());
}