code: public String filter (String msg, Name otherUser, boolean outgoing)
      {
          // we are only concerned with filtering things going to or coming
          // from muted users
          if ((otherUser != null) && isMuted(otherUser)) {
              // if it was outgoing, explain the dropped message, otherwise
              // silently drop
              if (outgoing) {
                  _chatdir.displayFeedback(null, "m.no_tell_mute");
              }
              return null;
          }
  
          return msg;
      }
docs: documentation inherited from interface ChatFilter