public RenderBuffer createDestructableClone() {
            if (tex != null) {
                return null;
            } else {
                RenderBuffer destructClone = new RenderBuffer();
                destructClone.id = id;
                return destructClone;
            }
        }
Do not use.

@return the slot code, such as SLOT_DEPTH_STENCIL
jme3-core/src/main/java/com/jme3/texture/FrameBuffer.java