anchor.diff:  Logger _log = new Logger('jefe.project.jefe.impl');
   
   class JefeProjectImpl extends ProjectImpl
  -    with JefeProjectGraphMixin
  +    with _JefeProjectGraphMixin
       implements JefeProject, JefeProjectGraph {
     @override
     final JefeProjectSet directDependencies;
  
positive.code: }
  
  class JefeProjectSetImpl extends DelegatingSet<JefeProject>
      with JefeProjectGraphMixin
      implements JefeProjectSet {
    JefeProjectSetImpl(Set<JefeProject> base) : super(base);
  
  
negative.code:       expand/*<JefeProject>*/((n) => n.getDepthFirst(visited));
  }
  
  abstract class _JefeProjectGraphMixin implements JefeProjectGraph {
    Iterable<JefeProject> get depthFirst => getDepthFirst(new Set<JefeProject>());
  
    Future processDepthFirst(
        process(JefeProject project, Iterable<JefeProject> dependencies)) async {
      return await Future.forEach(
          depthFirst, (JefeProject p) => process(p, p.directDependencies));
    }
  }
  