public boolean isSet(_Fields field) {
    if (field == null) {
      throw new IllegalArgumentException();
    }

    switch (field) {
    case SESSION_IDS:
      return isSetSessionIds();
    case WHO:
      return isSetWho();
    }
    throw new IllegalStateException();
  }
public boolean isSet ( _Fields field ) { if ( field == null ) { throw new IllegalArgumentException ( ) ; } switch ( field ) { case SESSION_IDS : return isSetSessionIds ( ) ; case WHO : return isSetWho ( ) ; } throw new IllegalStateException ( ) ; }
Returns true if field corresponding to fieldID is set (has been assigned a value) and false otherwise