docs: function _loadRecursive(container, map, accum = {}) {
    return Bluebird.reduce(Object.keys(map), (memo, key) => {
      const path = map[key];
      if (typeof path === 'string') {
        return container._load(path)
          .then((mod) => {
            set(memo, key, mod);
            return memo;
          });
      }
      return _loadRecursive(container, path)
        .then((mods) => {
          set(memo, key, mods);
          return memo;
        });
    }, accum);
  }