public Vector4f addLocal(float addX, float addY, float addZ, float addW) {
        x += addX;
        y += addY;
        z += addZ;
        w += addW;
        return this;
    }
<code>addLocal</code> adds the provided values to this vector
internally, and returns a handle to this vector for easy chaining of
calls.

@param addX
           value to add to x
@param addY
           value to add to y
@param addZ
           value to add to z
@param addW
           the w value to add.
@return this
jme3-core/src/main/java/com/jme3/math/Vector4f.java