Refactor. Fires marker calibration

lib/dummyMapPlugin.dart

@@ -0,0 +1,27 @@
+import 'package:flutter/src/widgets/framework.dart';
+import 'package:flutter_map/plugin_api.dart';
+import 'package:flutter/material.dart';
+
+class DummyMapPluginOptions extends LayerOptions {
+  final String text;
+
+  DummyMapPluginOptions({this.text = ""});
+}
+
+// https://github.com/apptreesoftware/flutter_map/blob/master/flutter_map_example/lib/pages/plugin_api.dart
+class DummyMapPlugin extends MapPlugin {
+
+  @override
+  Widget createLayer(LayerOptions options, MapState mapState) {
+    if (options is DummyMapPluginOptions) {
+      return const SizedBox();
+    }
+    throw ("Unknown options type for DummyMapPlugin"
+        "plugin: $options");
+  }
+
+  @override
+  bool supportsLayer(LayerOptions options) {
+    return options is DummyMapPluginOptions;
+  }
+}