public static Integer mapKey(final byte[] b) {
    return hashCode(b);
  }
Calculate a hash code from a given byte array suitable for use as a key in maps.
@param b bytes to hash
@return A hash of <code>b</code> as an Integer that can be used as key in Maps.
hbase-common/src/main/java/org/apache/hadoop/hbase/util/Bytes.java