Move MapQueryValues to the proper file

angel_orm/lib/src/map_query_values.dart

@@ -0,0 +1,9 @@
+import 'query_values.dart';
+
+/// A [QueryValues] implementation that simply writes to a [Map].
+class MapQueryValues extends QueryValues {
+  final Map<String, dynamic> values = {};
+
+  @override
+  Map<String, dynamic> toMap() => values;
+}

angel_orm/lib/src/query_values.dart

@@ -56,12 +56,4 @@ abstract class QueryValues {
     }
     return b.toString();
   }
-}
+}
-
-/// A [QueryValues] implementation that simply writes to a [Map].
-class MapQueryValues extends QueryValues {
-  final Map<String, dynamic> values = {};
-
-  @override
-  Map<String, dynamic> toMap() => values;
-}