Editor User Guide
The Runner allows you to run your extension and see the requests and responses. From within the runner, you can view the headers sent with your request, view the type and contents of the request, alter the request manually and run it again, and see the history of past runs. You also, of course, see the responses. This provides an excellent testing and debugging tool with all manner of potential uses.
In the Runner, you can run your task, altering the HTTP method, the URL parameters, or the headers of your request, so that you can optimize debugging and testing of your extension.
You can also alter the body of the request, in order to send test data to your task.
Lastly, you can also see the history of previous calls which will prove useful when conducting testing using different parameters and comparing results.