broadcast method
Sends an event to all clients.
Implementation
void broadcast(String eventName, data,
    {Function(WebSocketContext socket)? filter}) {
  ws.batchEvent(WebSocketEvent(eventName: eventName, data: data),
      filter: filter);
}
Sends an event to all clients.
void broadcast(String eventName, data,
    {Function(WebSocketContext socket)? filter}) {
  ws.batchEvent(WebSocketEvent(eventName: eventName, data: data),
      filter: filter);
}