code: @Override
    public NettyChannelBuilder keepAliveTime(long keepAliveTime, TimeUnit timeUnit) {
      checkArgument(keepAliveTime > 0L, "keepalive time must be positive");
      keepAliveTimeNanos = timeUnit.toNanos(keepAliveTime);
      keepAliveTimeNanos = KeepAliveManager.clampKeepAliveTimeInNanos(keepAliveTimeNanos);
      if (keepAliveTimeNanos >= AS_LARGE_AS_INFINITE) {
        // Bump keepalive time to infinite. This disables keepalive.
        keepAliveTimeNanos = KEEPALIVE_TIME_NANOS_DISABLED;
      }
      return this;
    }
docs: {@inheritDoc}
  
  @since 1.3.0