--- a/http/src/luan/modules/http/Http.luan	Wed Jul 08 23:10:52 2015 -0600
+++ b/http/src/luan/modules/http/Http.luan	Sun Jul 12 21:34:23 2015 -0600
@@ -1,12 +1,12 @@
 java()
 local Luan = require "luan:Luan"
-local ipairs = Luan.ipairs
-local pairs = Luan.pairs
 local error = Luan.error
-local set_metatable = Luan.set_metatable
+local ipairs = Luan.ipairs or error()
+local pairs = Luan.pairs or error()
+local set_metatable = Luan.set_metatable or error()
 local Io = require "luan:Io"
 local Html = require "luan:Html"
-local url_encode = Html.url_encode
+local url_encode = Html.url_encode or error()
 local HttpServicer = require "java:luan.modules.http.HttpServicer"
 local IoLuan = require "java:luan.modules.IoLuan"
 
@@ -31,6 +31,13 @@
 	end
 end
 
+local function sent_error()
+	error "headers are not accessible after you start writing content"
+end
+
+M.sent_error_metatable = { __index=sent_error, __new_index=sent_error }
+
+
 
 local function new_common(this)
 	this = this or {}
@@ -104,6 +111,7 @@
 
 		function this.set()
 			HttpServicer.setResponse(this,this.java)
+			set_metatable(this.headers,M.sent_error_metatable)
 		end
 
 		function this.text_writer()