Project lint checked and step added to config.yml

lib/data/prefs/preference_provider.dart

@@ -0,0 +1,25 @@
+import 'package:shared_preferences/shared_preferences.dart';
+
+import 'currency_pair.dart';
+
+const String currencyOne = "conversion_one";
+const String currencyTwo = "conversion_two";
+class PreferenceProvider {
+  late final SharedPreferences _prefs;
+
+  Future<void> init() async {
+    _prefs = await SharedPreferences.getInstance();
+  }
+
+  Future<void> saveConversionPair(String s1, String s2) async {
+    await _prefs.setString(currencyOne, s1);
+    await _prefs.setString(currencyTwo, s2);
+  }
+
+  CurrencyPair getConversionPair() {
+    String? s1 = _prefs.getString(currencyOne);
+    String? s2 = _prefs.getString(currencyTwo);
+
+    return CurrencyPair(s1, s2);
+  }
+}