outReq := new(http.Request)
	*outReq = *inReq // includes shallow copies of maps, but we handle this in Director

	revproxy := httputil.ReverseProxy{
		Director: func(req *http.Request) {
			f.modifyRequest(req, inReq.URL)
		},
		BufferPool:    newBufPool(128 << 10),
		Transport:     f.RoundTripper,
		FlushInterval: defaultFlushInterval,
		ErrorHandler:  f.customErrHandler,
	}

	if f.ErrorHandler != nil {