AJAX HTTP error on wsclient REST service I'm trying out the wsclient in Drupal 7 and whenever I attempt to test the the transaction to another API using REST I get the following error:

An AJAX HTTP error occurred.
HTTP Result Code: 200
Debugging information follows.
Path: /system/ajax
StatusText: OK
ResponseText: 
Fatal error:  Call to undefined method HttpClient::__getLastRequestHeaders() in /home/dmwbm/www/sites/default/modules/wsclient/wsclient_tester/wsclient_tester.inc on line 143


Looking at the error it appears that this is an attribute required by the SOAP service. The SOAP examples are the only ones that work and the REST ones do not. 

A friend suggested running this suite on simplytest.me so that I could isolate what is conflicting in my drupal install. Wouldn't you know, this message is output on this clean Drupal install. 

Googling I see this error in a bug fix from two years ago. I must be doing something wrong in that this error should have been fixed by now and shouldn't show up in my install or simplytest.me. What obvious thing am I overlooking? thx, sam
It appears that both examples provided by the author no longer work, most likely because the API's changed. See link to author page above.