code: function scan (moduleName, first)
    {
      var module = context.modules[moduleName];
      if (!module)
        throw new Error (sprintf ("Module '%' was not found.", moduleName));
      // Ignore the module if it's external.
      if (module.external)
        return false;
      if (!module.optimize) {
        if (first)
          module.nonOptimizedContainer = true;
        disableOptimizationsForChildrenOf (module);
        return true;
      }
      for (var i = 0, m = module.requires.length, any = false; i < m; ++i)
        if (scan (module.requires[i])) //Note: scan() still must be called for ALL submodules!
          any = true;
      if (any)
        module.nonOptimizedContainer = true;
      return false;
    }
docs: Search for unoptimizable modules.
  @param {string} moduleName
  @param {boolean?} first=false Is this the root module?
  @returns {boolean} `true` if the module is not optimizable.