@Override
  public boolean equals(Object other) {
    if (other == null) {
      return false;
    }
    if (other instanceof AuthenticationTokenIdentifier) {
      AuthenticationTokenIdentifier ident = (AuthenticationTokenIdentifier) other;
      return sequenceNumber == ident.getSequenceNumber() && keyId == ident.getKeyId()
        && issueDate == ident.getIssueDate() && expirationDate == ident.getExpirationDate()
        && (username == null ? ident.getUsername() == null : username.equals(ident.getUsername()));
    }
    return false;
  }
Represents the identity information stored in an HBase authentication token.
hbase-client/src/main/java/org/apache/hadoop/hbase/security/token/AuthenticationTokenIdentifier.java