Error when browser refresh about php-push-websocket HOT 2 CLOSED

if ($data === false) {
    $this->__disconnect($client, 'Client data equal to "false"');
}
# if the socket_read returns false, disconnect the client
elseif ($data === null) {
    $this->__disconnect($client, 'Client data equal to "null"');
}
elseif (empty($data)) {
    $this->__disconnect($client, 'Client data empty, we assume it is disconnected');
}
# if no handshake is made yet, make one
elseif (!$client->getHandshake()) {
    if (!$this->__handshake($client, $data)) {
        $this->__disconnect($client, 'Could not make handshake');
    }
}
elseif (bin2hex($unmasked = $this->__unmask($data)) == 03e9) {
    $this->__disconnect($client, 'Unmasked client data equal to "03e9"');
}
# We have "valid" data to do stuff with
else {
    $this->__action($client, $unmasked);
}