Kqueue.Timeout.t is the timespan in nanoseconds that is used to represent the maximum amount of time the kevent call should wait for an event.

never results in the kevent call to wait indefinitely for a new event.

Note: Unlike Unix.select, if the user calls kevent with an empty eventlist, the kevent call returns immediately event when a timeout value of never is used.

immediate effects a poll, and the kevent call will return immediately, without waiting for new events if none are available at the time of the call.

of_ns creates a new timeout from nanoseconds.