anchor.diff:  -define(VIEW_PLUGIN, #plugin{name = views,
                                proxy_strategy = local,
                                rest_api_prefix = "couchBase",
  -                             doc_root = "",
  +                             doc_roots = [],
                                request_headers_filter = {keep, ["accept",
                                                                 "accept-encoding",
                                                                 "accept-language",
  
positive.code: -record(plugin, { name            :: service_name(),
                    proxy_strategy  :: proxy_strategy(),
                    rest_api_prefix :: rest_api_prefix(),
                    doc_root        :: {multiple_roots, [string()]} | string(),
                    request_headers_filter :: {filter_op(), [string()]}}).
  -type plugin()  :: #plugin{}.
  -type plugins() :: [plugin()].
  
negative.code: %%% =============================================================
  %%%
  maybe_serve_file(RestPrefix, Plugins, Req, Path) ->
      case doc_roots(RestPrefix, Plugins) of
          DocRoots when is_list(DocRoots) ->
              serve_file_multiple_roots(Req, Path, DocRoots);
          undefined ->
              menelaus_util:reply_not_found(Req)
      end.
  
  doc_roots(RestPrefix, Plugins) ->
      case find_plugin_by_prefix(RestPrefix, Plugins) of
          #plugin{doc_roots = DocRoots} ->
              DocRoots;
          false ->
              undefined
      end.
  