class TestClock

final class TestClock implements ClockInterface {
    public const DEFAULT_START_EPOCH = 1633060331386955008;
    // Fri Oct 01 2021 03:52:11 UTC
    private int $currentEpochNanos;
    public function __construct(int $currentEpochNanos = self::DEFAULT_START_EPOCH) {
        $this->currentEpochNanos = $currentEpochNanos;
    }
    public function advanceSeconds(int $seconds = 1) : void {
        $this->advance($seconds * ClockInterface::NANOS_PER_SECOND);
    }
    public function advance(int $nanoSeconds = 1) : void {
        $this->currentEpochNanos += $nanoSeconds;
    }
    public function setTime(int $nanoSeconds) : void {
        $this->currentEpochNanos = $nanoSeconds;
    }
    public function now() : int {
        return $this->currentEpochNanos;
    }

}