Aerys\Websocket\Rfc6455Endpoint::send PHP Method

    public function send($clientId, string $data, bool $binary = false) : Promise
    {
        if ($clientId === null) {
            $clientId = array_keys($this->clients);
        }
        if (\is_array($clientId)) {
            $promises = [];
            foreach ($clientId as $id) {
                $promises[] = $this->send($id, $data, $binary);
            }
            return all($promises);
        }
        if ($client = $this->clients[$clientId] ?? null) {
            $client->messagesSent++;
            $opcode = $binary ? self::OP_BIN : self::OP_TEXT;
            assert($binary || preg_match("//u", $data), "non-binary data needs to be UTF-8 compatible");
            if (\strlen($data) > 1.5 * $this->autoFrameSize) {
                $len = \strlen($data);
                $slices = ceil($len / $this->autoFrameSize);
                $frames = str_split($data, ceil($len / $slices));
                $data = array_pop($frames);
                foreach ($frames as $frame) {
                    $this->compile($client, $frame, $opcode, false);
                    $opcode = self::OP_CONT;
                }
            }
            return $this->compile($client, $data, $opcode);
        }
        return new Success();
    }