 	on the IPv4 server socket.
 	
 	*/
-	fileprivate var dispatch_source_ipv4:DispatchSource!
+	fileprivate var dispatch_source_ipv4:DispatchSourceRead!
 	
 	
 	/**

			throw SocketError.listen
		}
		
		dispatch_source_ipv4 = DispatchSource.makeReadSource(fileDescriptor: socket_ipv4, queue: DispatchQueue.global()) /*Migrator FIXME: Use DispatchSourceRead to avoid the cast*/ as! DispatchSource
		dispatch_source_ipv4.setEventHandler
		{
			self.acceptConnection(self.socket_ipv4)
		}
		dispatch_source_ipv4.resume()
		
		dispatch_source_ipv6 = DispatchSource.makeReadSource(fileDescriptor: socket_ipv6, queue: DispatchQueue.global()) /*Migrator FIXME: Use DispatchSourceRead to avoid the cast*/ as! DispatchSource
		dispatch_source_ipv6.setEventHandler
		{
			self.acceptConnection(self.socket_ipv6)

	on the IPv6 server socket.
	
	*/
	fileprivate var dispatch_source_ipv6:DispatchSourceRead!
	
	
	/**
