Represents a client-side HTTP request.

Instances are created by an HttpClient instance, via one of the methods corresponding to the specific HTTP methods, or the generic request method. Once a request has been obtained, headers can be set on it, and data can be written to its body if required. Once you are ready to send the request, the end() method should be called.

Nothing is actually sent until the request has been internally assigned an HTTP connection. The HttpClient instance will return an instance of this class immediately, even if there are no HTTP connections available in the pool. Any requests sent before a connection is assigned will be queued internally and actually sent when an HTTP connection becomes available from the pool.

The headers of the request are actually sent either when the end() method is called, or, when the first part of the body is written, whichever occurs first.

This class supports both chunked and non-chunked HTTP.

An example of using this class is as follows:

HttpClientRequest req = client.
  request(post, "/some-url").
  headers { "some-header"->"hello", "Content-Length"->"5" };
req.response.onComplete((HttpClientResponse resp) => print("Got response ``resp.status``"));
req.end("hello");

Instances of HttpClientRequest are not thread-safe.