/**
 * Test HttpResponse.
 */
function test_HttpResponse()
{
    HttpResponse::setCache(true);
    HttpResponse::setContentType('application/pdf');
    HttpResponse::setContentDisposition("test.pdf", false);
    HttpResponse::setFile('sheet.pdf');
    HttpResponse::send();
}
<?php

// send 5000 bytes every 0.2 seconds, i.e. max ~25kByte/s
HttpResponse::setThrottleDelay(0.2);
HttpResponse::setBufferSize(5000);
HttpResponse::setCache(true);
HttpResponse::setContentType('application/x-zip');
HttpResponse::setFile('../archive.zip');
HttpResponse::send();