Replace NEKit dependency with reduced subset

GlassVPN/zhuhaow-NEKit/Socket/AdapterSocket/RejectAdapter.swift

@@ -0,0 +1,49 @@
+import Foundation
+
+public class RejectAdapter: AdapterSocket {
+    public let delay: Int
+
+    public init(delay: Int) {
+        self.delay = delay
+    }
+
+    override public func openSocketWith(session: ConnectSession) {
+        super.openSocketWith(session: session)
+
+        QueueFactory.getQueue().asyncAfter(deadline: DispatchTime.now() + DispatchTimeInterval.milliseconds(delay)) {
+            [weak self] in
+            self?.disconnect()
+        }
+    }
+
+    /**
+     Disconnect the socket elegantly.
+     */
+    public override func disconnect(becauseOf error: Error? = nil) {
+        guard !isCancelled else {
+            return
+        }
+
+        _cancelled = true
+        session.disconnected(becauseOf: error, by: .adapter)
+        observer?.signal(.disconnectCalled(self))
+        _status = .closed
+        delegate?.didDisconnectWith(socket: self)
+    }
+
+    /**
+     Disconnect the socket immediately.
+     */
+    public override func forceDisconnect(becauseOf error: Error? = nil) {
+        guard !isCancelled else {
+            return
+        }
+
+        _cancelled = true
+        session.disconnected(becauseOf: error, by: .adapter)
+        observer?.signal(.forceDisconnectCalled(self))
+        _status = .closed
+        delegate?.didDisconnectWith(socket: self)
+    }
+
+}