added optional delayMs param

CHANGELOG.md

+## [4.0.3]
+
+- Added optional delay param to `disconnect` method
+
 ## [4.0.2]
 
 - Fixed IP bug

lib/src/network_printer.dart

@@ -44,8 +44,12 @@ class NetworkPrinter {
     }
   }
 
-  void disconnect() {
+  /// [delayMs]: milliseconds to wait after destroying the socket
+  void disconnect({int delayMs}) async {
     _socket.destroy();
+    if (delayMs != null) {
+      await Future.delayed(Duration(milliseconds: delayMs), () => null);
+    }
   }
 
   // ************************ Printer Commands ************************

pubspec.yaml

 name: esc_pos_printer
 description: The library allows to print receipts using an ESC/POS thermal WiFi printer.
-version: 4.0.2
+version: 4.0.3
 homepage: https://github.com/andrey-ushakov/esc_pos_printer
 
 environment: