move dispose to the bottom

@@ -38,11 +38,6 @@ abstract class MobileScannerPlatform extends PlatformInterface {
     throw UnimplementedError('buildCameraView() has not been implemented.');
   }
 
-  /// Dispose of this [MobileScannerPlatform] instance.
-  void dispose() {
-    throw UnimplementedError('dispose() has not been implemented.');
-  }
-
   /// Reset the zoom scale, so that the camera is fully zoomed out.
   Future<void> resetZoomScale() {
     throw UnimplementedError('resetZoomScale() has not been implemented.');
@@ -91,4 +86,9 @@ abstract class MobileScannerPlatform extends PlatformInterface {
   Future<void> updateScanWindow(Rect? window) {
     throw UnimplementedError('updateScanWindow() has not been implemented.');
   }
+
+  /// Dispose of this [MobileScannerPlatform] instance.
+  void dispose() {
+    throw UnimplementedError('dispose() has not been implemented.');
+  }
 }