clean up

lib/domain/entities/market.dart

@@ -0,0 +1,28 @@
+class Market {
+  String id;
+  String name;
+
+  Market({
+    this.id,
+    this.name,
+  });
+
+  Map<String, dynamic> toMap() {
+    return {
+      'id': id,
+      'name': name,
+    };
+  }
+
+  factory Market.fromMap(Map<String, dynamic> map, String id) {
+    return Market(
+      id: id,
+      name: map['name'],
+    );
+  }
+
+  @override
+  String toString() {
+    return 'Market{id: $id, name: $name}';
+  }
+}