code: static synchronized List<Watcher> get(Context context) {
          List<Watcher> watchers;
          if (context.contains(WATCHERS_KEY)) {
              try {
                  watchers = (List<Watcher>) context.get(WATCHERS_KEY);
              } catch (ContextException e) {
                  throw new IllegalStateException("Cannot extract the watcher from the context", e);
              }
          } else {
              watchers = new ArrayList<>();
              context.put(WATCHERS_KEY, watchers);
          }
          return watchers;
      }
docs: Gets the list of watchers from the given Plexus context.
  
  @param context the Plexus context
  @return the list of watcher, empty if none. Modifying the resulting list, updates the stored list.