Add a toString method to ApfCapabilities.

        this.maximumApfProgramSize = maximumApfProgramSize;

        this.apfPacketFormat = apfPacketFormat;

    }

    public String toString() {

        return String.format("%s{version: %d, maxSize: %d format: %d}", getClass().getSimpleName(),

                apfVersionSupported, maximumApfProgramSize, apfPacketFormat);

    }

}