|  | <!doctype html> | 
|  | <html> | 
|  | <head> | 
|  | <title>XMLHttpRequest: setRequestHeader() after send()</title> | 
|  | <script src="/resources/testharness.js"></script> | 
|  | <script src="/resources/testharnessreport.js"></script> | 
|  | <link rel="help" href="https://xhr.spec.whatwg.org/#the-setrequestheader()-method" data-tested-assertations="/following::ol/li[2]" /> | 
|  | </head> | 
|  | <body> | 
|  | <div id="log"></div> | 
|  | <script> | 
|  | var test = async_test() | 
|  | test.step(function() { | 
|  | var client = new XMLHttpRequest() | 
|  | client.open("GET", "resources/delay.py?ms=0") | 
|  | client.onreadystatechange = function() { | 
|  | test.step(function() { | 
|  | assert_throws("InvalidStateError", function() { client.setRequestHeader("x-test", "test") }) | 
|  | if(client.readyState == 4) | 
|  | test.done() | 
|  | }) | 
|  | } | 
|  | client.send(null) | 
|  | }) | 
|  | </script> | 
|  | </body> | 
|  | </html> |