@Override
        public String toString() {
            if (tex != null) {
                return "TextureTarget[format=" + format + "]";
            } else {
                return "BufferTarget[format=" + format + "]";
            }
        }
Do not use.

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