Use custom packet flow implementation for testing

OpenVPN Adapter Tests/CustomFlow.swift

@@ -9,12 +9,20 @@ import NetworkExtension
 
 class CustomFlow: NEPacketTunnelFlow {
 
+    override func readPackets(completionHandler: @escaping ([Data], [NSNumber]) -> Void) {
+        
+    }
+    
+    override func writePackets(_ packets: [Data], withProtocols protocols: [NSNumber]) -> Bool {
+        return true
+    }
+    
     override func readPacketObjects(completionHandler: @escaping ([NEPacket]) -> Void) {
-        super.readPacketObjects(completionHandler: completionHandler)
+        
     }
     
     override func writePacketObjects(_ packets: [NEPacket]) -> Bool {
-        return super.writePacketObjects(packets)
+        return true
     }
     
 }