code: public static synchronized boolean remove(MavenSession session, Watcher watcher) {
          return !(session == null || watcher == null) && get(session).remove(watcher);
      }
docs: Un-registers a watcher.
  
  @param session the Maven session
  @param watcher the watcher to remove
  @return {@literal true} if the watcher was removed, {@literal false} otherwise.