Merge pull request #557 from naderio/master

add SocketAckEmitter.expected to indicate if an ack is expected by server

Author: nuclearace

Source/SocketAckEmitter.swift

@@ -27,6 +27,10 @@ import Foundation
 public final class SocketAckEmitter : NSObject {
     let socket: SocketIOClient
     let ackNum: Int
+
+    public var expected: Bool {
+        return ackNum != -1
+    }
 
     init(socket: SocketIOClient, ackNum: Int) {
         self.socket = socket
@@ -44,6 +48,7 @@ public final class SocketAckEmitter : NSObject {
 
         socket.emitAck(ackNum, with: items)
     }
+        
 }
 
 public final class OnAckCallback : NSObject {