1 CONSOLE WARNING: Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. For more help, check http://xhr.spec.whatwg.org/.
2 Test that setRequestHeader throws a SYNTAX_ERR exception when called with an empty header name.
4 SUCCESS: got exception SyntaxError: Failed to execute 'setRequestHeader' on 'XMLHttpRequest': '' is not a valid HTTP header field name.