/**
  * Add an event line to the channel, if it's of type that should be displayed.
  *
  * @param line
  * @return <code>true</code> if the channel accepted the message, <code>false</code> otherwise
  */
 boolean addEventLine(final EventLine line) {
   if (eventTypes.contains(line.getType())) {
     channel.addLine(line);
     return true;
   }
   return false;
 }
 /** Clear the channel log. */
 void clear() {
   channel.clear();
 }