anchor.diff:        return await _executeOnConcurrentProjects(
             await _projectGroup.rootJefeProjects, command, filter);
       } else {
  -      return await _processDependenciesDepthFirst(
  -          (JefeProject project) async {
  +      return await _processDependenciesDepthFirst((JefeProject project) async {
           if (_filter(project)) {
             return await command.process(project);
           }
  
positive.code:     }
      final jefeProject = jefeProjectOpt.get();
  
      return await command.process(jefeProject.project,
          dependencies: jefeProject.directDependencies);
    }
  
    Future executeOnGraph(ProjectDependencyGraphCommand command,
  
negative.code:     return await new Stream.fromIterable(
              projectGraph.depthFirst.map((JefeProject pd) async {
        if (filter(pd)) {
          return await command.process(pd);
        }
      }).toList())
          .asyncMap((result) => result)
  