Kind of request (See HTTPMethod enum).
Location to request. For a request on https://github.com/rejectedsoftware/vibe.d/issues?q=author%3ASantaClaus, it will be '/rejectedsoftware/vibe.d/issues'.
The headers to send. Some field might be overriden (such as Content-Length). However, Content-Type will NOT be overriden.
The encoded query string. For a request on https://github.com/rejectedsoftware/vibe.d/issues?q=author%3ASantaClaus, it will be 'author%3ASantaClaus'.
The body to send, as a string. If a Content-Type is present in hdrs, it will be used, otherwise it will default to the generic type "application/json".
A map of required return headers. To avoid returning unused headers, nothing is written to this structure unless there's an (usually empty) entry (= the key exists) with the same key. If any key present in reqReturnHdrs is not present in the response, an Exception is thrown.
A map of optional return headers. This behaves almost as exactly as reqReturnHdrs, except that non-existent key in the response will not cause it to throw, but rather to set this entry to 'null'.
The Json object returned by the request
Perform a request to the interface using the given parameters.