final public static int len(byte[] b) {
        return b == null
                ? 0
                : b.length;
    }
Returns length of the byte array, returning 0 if the array is null. Useful for calculating
sizes.

@param b byte array, which can be null
@return 0 if b is null, otherwise returns length
stroom-bytebuffer/src/main/java/stroom/bytebuffer/hbase/Bytes.java