sleepAsync

import dpromise.utils : runEventloop;
import std.datetime : Clock, SysTime, UTC;

auto startTime = Clock.currTime(UTC());

sleepAsync(100.msecs).then({
  auto dur = Clock.currTime(UTC()) - startTime;
  assert(dur + 4.msecs > 100.msecs);
  assert(dur - 4.msecs < 100.msecs);
});

runEventloop();