| <!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> |