code: function purgeCache(moduleName) {
    return searchAndProcessCache(moduleName, function (mod) {
      delete require.cache[mod.id];
    })
    .then(() => {
      _.forEach(_.keys(module.constructor._pathCache), function(cacheKey) {
        if (cacheKey.indexOf(moduleName)>0) {
          delete module.constructor._pathCache[cacheKey];
        }
      });
      return BbPromise.resolve();
    });
  }
docs: Remove the specified module from the require cache.
  @param {string} moduleName