private byte[] removeHeader(@NonNull final byte[] data, final int offset, final int length) {
        final ByteBuffer buffer = ByteBuffer.allocate(length).order(ByteOrder.BIG_ENDIAN);
        buffer.put(data, offset, length);
        return buffer.array();
    }
Removes the header from a given array.

@param data   message.
@param offset header offset.
@param length header length.
@return an array without the header.
mesh/src/main/java/no/nordicsemi/android/mesh/transport/LowerTransportLayer.java