@Override
  public final boolean equals(Object o) {
    // SaslClientAuthProviders should be unique via their hashCode().
    if (o instanceof AbstractSaslClientAuthenticationProvider) {
      return this.hashCode() == o.hashCode();
    }
    return false;
  }
Provides a hash code to identify this AuthenticationProvider among others. These two fields
must be unique to ensure that authentication methods are clearly separated.
hbase-client/src/main/java/org/apache/hadoop/hbase/security/provider/AbstractSaslClientAuthenticationProvider.java