Google\Cloud\PubSub\Connection\Grpc::publishMessage PHP Method

    public function publishMessage(array $args)
    {
        $pbMessages = [];
        $messages = $this->pluck('messages', $args);
        foreach ($messages as $message) {
            $pbMessages[] = $this->buildMessage($message);
        }
        return $this->send([$this->publisherClient, 'publish'], [$this->pluck('topic', $args), $pbMessages, $args]);
    }