|  | <!DOCTYPE html> | 
|  | <html> | 
|  | <head> | 
|  | <title>XMLHttpRequest: getResponseHeader() in unsent, opened states</title> | 
|  | <script src="/resources/testharness.js"></script> | 
|  | <script src="/resources/testharnessreport.js"></script> | 
|  | <link rel="help" href="https://xhr.spec.whatwg.org/#dom-xmlhttprequest-getresponseheader" data-tested-assertations="/following::OL[1]/LI[1]" /> | 
|  | </head> | 
|  | <body> | 
|  | <div id="log"></div> | 
|  | <script> | 
|  | var test = async_test() | 
|  | test.step(function() { | 
|  | var client = new XMLHttpRequest() | 
|  | assert_equals(client.getResponseHeader("x-custom-header"), null) | 
|  | client.onreadystatechange = function() { | 
|  | test.step(function() { | 
|  | if(client.readyState < 2) { | 
|  | assert_equals(client.getResponseHeader("x-custom-header"), null) | 
|  | assert_equals(client.getResponseHeader("CONTENT-TYPE"), null) | 
|  | test.done() | 
|  | } | 
|  | }) | 
|  | } | 
|  | client.open("GET", "resources/headers.py") | 
|  | assert_equals(client.getResponseHeader("x-custom-header"), null) | 
|  | assert_equals(client.getResponseHeader("Date"), null) | 
|  | client.send(null) | 
|  | }) | 
|  | </script> | 
|  | </body> | 
|  | </html> |