title: Instance of 'Future<bool>, but expect bool
body: <p>I am new in flutter.And i have a question.I have method checkIsExistByString to check if i have a data before to insert date in sqflite.I expect true or false. </p>
  
  <pre><code>class DbManager {
  
      Future&lt;bool&gt; checkIsExistByString(String title) async {
  
              await openDb();
              var result = await _database
                  .rawQuery('SELECT $Title FROM $tableName WHERE $Title = ?', [title]);
  
              return Future&lt;bool&gt;.value(result.isEmpty ? true : false);
            }
  }
  </code></pre>
  
  <p>When i try to use checkIsExistByString i expect bool, but i have Instance of 'Future</p>
  
  <pre><code>void _submit() async {
  
      print(dbmanager.checkIsExistByString('Title'));//print -- Instance of 'Future&lt;bool&gt;',but i expect true
  
     ...
    }
  </code></pre>