code: public GrpcServerBuilder keepAliveTimeout(long keepAliveTimeout, TimeUnit timeUnit) {
      mNettyServerBuilder = mNettyServerBuilder.keepAliveTimeout(keepAliveTimeout, timeUnit);
      return this;
    }
docs: Sets the keep alive timeout.
  
  @param keepAliveTimeout time to wait after pinging client before closing the connection
  @param timeUnit unit of the timeout
  @return an updated instance of this {@link GrpcServerBuilder}