@Override
  public boolean equals(Object obj) {
    if (obj == null || !(obj instanceof NonceKey)) {
      return false;
    }
    NonceKey nk = ((NonceKey) obj);
    return this.nonce == nk.nonce && this.group == nk.group;
  }
This implementation is not smart and just treats nonce group and nonce as random bits.
hbase-common/src/main/java/org/apache/hadoop/hbase/util/NonceKey.java