@Override
    public void write(JmeExporter e) throws IOException {
        OutputCapsule capsule = e.getCapsule(this);
        capsule.write(x, "x", 0);
        capsule.write(y, "y", 0);
    }
Serializes the vector to the specified exporter, for example when saving
to a J3O file. The current instance is unaffected.

@param e the exporter to use (not null)
@throws IOException from the exporter
jme3-core/src/main/java/com/jme3/math/Vector2f.java