From 1064646b20acef06caf4947122a99647c51773f0 Mon Sep 17 00:00:00 2001
From: Maik Riechert <maik.riechert@arcor.de>
Date: Thu, 24 Mar 2016 15:40:40 +0000
Subject: [PATCH] don't send empty Prefer header

---
 src/api.js | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/api.js b/src/api.js
index ad0c2cb..b35d21b 100644
--- a/src/api.js
+++ b/src/api.js
@@ -386,6 +386,9 @@ export class API {
     if (options.range) {
       uris.push(Range)
     }
+    if (uris.length === 0) {
+      return {}
+    }
     return {
       Prefer: 'return=representation; ' + 
               'include="' + uris.join(' ') + '"'