Format all tests.

tests/language/regress_16640_test.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // Regression test for issue 16640.
 
-class Segment extends SegmentGen { }
+class Segment extends SegmentGen {}
 
-class SegmentGen extends ConceptEntity<Segment> { }
+class SegmentGen extends ConceptEntity<Segment> {}
 
-class ConceptEntity<E> { }
+class ConceptEntity<E> {}
 
 main() {
   new ConceptEntity<Segment>();
 }