Useful tool to test httpd responses
Sometimes when you are testing, you need to test various HTTP scenarios. Usually, this is to ensure that the server has the proper response or your testing custom responses.
The best solution would be a simple HTTP Request & Response Service.
The one that gives you more bang for your testing would be httpbin.org.
Testing an HTTP Library can become difficult sometimes. RequestBin is fantastic for testing POST requests, but doesn't let you control the response. This exists to cover all kinds of HTTP scenarios. Additional endpoints are being considered.