/span><span class="identifier">prepare_payload</span></code></a> will remove
                  "chunked" from the Transfer-Encoding field if it appears
                  as the last encoding, and will set the Content-Length field to
                  the returned value.
                </p>
                <p>
                  Otherwise, when the function is omitted:
                </p>
                <p>
                  * A call to <a class="link" href="../ref/boost__beast__http__message/payload_size.