Loop through REST header

So, if I unterstand this correctly you have a setup like this:

Project
    - Test Suite
        - Test Case
             - Test Step
                - REST Request

You can add a groovy script somewhere, in this example we add it directly after the REST request.

Project
    - Test Suite
        - Test Case
             - Test Step
                - REST Request
                - groovy script

Then you can add a bit of code to loop through the header values:

context.testCase.getTestStepByName("REST Request").getHttpRequest().getParams().each {
	log.info it.key
}

Here I had the values address and sensor, the output generated the same values..