CombineHandler takes variadic list of handlers and produces one handler that calls each handler in order.

NewServer returns a new `*ghttp.Server` that wraps an `httptest` server.

NewTLSServer returns a new `*ghttp.Server` that wraps an `httptest` TLS server.

NewUnstartedServer return a new, unstarted, `*ghttp.Server`.

Helper type for creating a RoundTripper from a function.