boolean addEventLine(final EventLine line){
  if (eventTypes.contains(line.getType())) {
    channel.addLine(line);
    return true;
  }
  return false;
}

boolean addEventLine ( final EventLine line ) { if ( eventTypes . contains ( line . getType ( ) ) ) { channel . addLine ( line ) ; return true ; } return false ; }
add an event line to the channel , if it ' s of type that should be displayed .
