public static void writeVariableBytes(OutputStream output, byte[] data, int width)
            throws SerializationException {
        writeNumber(output, data.length, width);
        writeFixedBytes(output, data);
    }
Write length prefixed sequence of bytes to the ouput stream.
The length prefix is encoded in big endian order.
@param data the data to be written.
@param width the width of the length prefix, in bytes.
@throws SerializationException if the length of {@code data} is too large to fit in
{@code width} bytes or {@code width} is negative.
common/src/main/java/org/conscrypt/ct/Serialization.java