@Override
            long toLong(byte[] bytes, int offset, int length) {
                long l = 0;
                for (int i = offset; i < offset + length; i++) {
                    l <<= 8;
                    l ^= bytes[i] & 0xFF;
                }
                return l;
            }
Returns the Unsafe-using Converter, or falls back to the pure-Java implementation if unable
to do so.
stroom-bytebuffer/src/main/java/stroom/bytebuffer/hbase/Bytes.java