...Once you've built your Request, you can specify the response handlers you want to use. .onData, .onString, .onJson, and .onError are available. You can chain them together to handle multiple response types, as they return a modified version of the Request. The body of the Request is built using the RequestBuilder @resultBuilder. It merges each RequestParam in the body into one CombinedParam object. This contains all the other params as children. When you run .call(), the children are filtered to find the Url, and any other optional parameters that may have been included.