Import expire_cache.

Author: guojiex

lib/search_data_source.dart

@@ -1,6 +1,7 @@
 import 'package:meta/meta.dart';
 import 'dart:async';
 import 'dart:convert';
+import 'package:expire_cache/expire_cache.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart' show rootBundle;
 

pubspec.yaml

@@ -27,6 +27,7 @@ dependencies:
   googleapis_auth: ^0.2.6
   english_words: ^3.1.5
   url_launcher: ^4.0.3
+  expire_cache: ^1.0.2
 
 dev_dependencies:
   test: ^1.5.1+1