Using PUT method in Spiratest rest api in Java.

Hi, 

I'm trying to update a test case using https://api.inflectra.com/Spira/Services/v4_0/RestService.svc/projects/{project_id}/test-cases. but not sure what parameters i need to pass for PUT method using Java. I do have the testcase_id 

It is not  clear from the online documentations  which parameter(s )need to be included in the header.  

My understanding, there are specific parameters need to be included in the header. 

Can you please provide me with a clear example. 

Thank you, 

AzMo.