@Override
    void assembleMessageParameters() {
        MeshLogger.debug(TAG, "Source address: " + Integer.toHexString(srcAddress));
        MeshLogger.debug(TAG, "Destination address: " + Integer.toHexString(dstAddress));
        MeshLogger.debug(TAG, "Period Log: " + Integer.toHexString(periodLog));
        final ByteBuffer paramsBuffer = ByteBuffer.allocate(5).order(ByteOrder.LITTLE_ENDIAN);
        paramsBuffer.putShort((short) srcAddress);
        paramsBuffer.putShort((short) dstAddress);
        paramsBuffer.put(periodLog);
        mParameters = paramsBuffer.array();
    }
Constructs ConfigHeartbeatSubscriptionSet message.

@param srcAddress Source address identifies the Heartbeat Subscription Source,
                  where the address shall be an unassigned address or a unicast address.
                  All other values are prohibited.
@param dstAddress Destination address identifies the Heartbeat Subscription destination,
                  where the address shall be an unassigned address,
                  the primary unicast address of the node, or a group address,
                  all other values are Prohibited.
@param periodLog  Period for sending Heartbeat messages.
@throws IllegalArgumentException if any illegal arguments are passed.
mesh/src/main/java/no/nordicsemi/android/mesh/transport/ConfigHeartbeatSubscriptionSet.java