anchor.diff:  import 'package:jefe/src/project_commands/project_command.dart';
   import 'package:jefe/src/project_commands/project_command_executor.dart';
   import 'package:logging/logging.dart';
  -import 'package:option/option.dart';
   
   Logger _log = new Logger('jefe.project.commands.impl');
   
  
positive.code:       {CommandConcurrencyMode concurrencyMode:
            CommandConcurrencyMode.concurrentProject,
        ProjectFilter filter: _noOpFilter}) async {
      final _filter = filter != null ? filter : _noOpFilter;
  
      final executionMode = concurrencyMode.index < command.concurrencyMode.index
          ? concurrencyMode
          : command.concurrencyMode;
  
      if (executionMode == CommandConcurrencyMode.concurrentProject ||
          executionMode == CommandConcurrencyMode.concurrentCommand) {
        return await _executeOnConcurrentProjects(
            await _projectGroup.rootJefeProjects, command, filter);
      } else {
        return await _processDependenciesDepthFirst((JefeProject project) async {
          if (_filter(project)) {
            return await command.process(project);
          }
        });
      }
    }
  
    Future _processDependenciesDepthFirst(
        Future process(JefeProject project)) async {
      return (await _projectGroup.rootJefeProjects).processDepthFirst(process);
    }
  
    Future executeAll(CompositeProjectCommand composite,
  
negative.code:       projectGraph.processAllConcurrently(command, filter: filter);
  
    Future _executeOnAllConcurrentProjects(
            ProjectCommand command, ProjectFilter filter) async =>
        _executeOnConcurrentProjects(
            await _projectGroup.rootJefeProjects, command, filter);
  
    Future executeOn(ProjectCommand command, String projectName) =>
        _executeOnAllConcurrentProjects(command, projectNameFilter(projectName));
  
    Future executeOnGraph(ProjectDependencyGraphCommand command,
        {ProjectFilter filter: _noOpFilter}) async {
  