anchor.diff:  import 'dart:async';
   import 'dart:collection';
   import 'dart:convert';
  -
  -import 'package:pub_semver/pub_semver.dart';
   
   import 'src/code_problem.dart';
   import 'src/fitness.dart';
  
positive.code:   Future<Summary> inspectPackage(
      String package, {
      String version,
      String packageDir,
      bool keepTransitiveLibs: false,
    }) async {
      var toolProblems = <ToolProblem>[];
      var sdkVersion = _dartSdk.version;
      log.info("SDK: $sdkVersion");
  
      log.info("Package: $package");
  
      Version ver;
      if (version != null) {
        ver = new Version.parse(version);
        log.info("Version: $ver");
      }
  
      if (_pubEnv.pubCacheDir != null) {
        log.fine("Using .package-cache: ${_pubEnv.pubCacheDir}");
      }
  
      var pkgDir;
      Version pkgVersion;
      if (packageDir != null) {
        log.info("Using package directory at $packageDir");
        pkgDir = packageDir;
      } else {
        log.info("Downloading package $package...");
        var pkgInfo =
            await _pubEnv.getLocation(package, version: ver?.toString());
        pkgDir = pkgInfo.location;
        pkgVersion = new Version.parse(pkgInfo.version);
        log.fine("Package at $pkgDir");
      }
  
      log.info('Counting files...');
      var dartFiles =
  
negative.code:       toolProblems.add(new ToolProblem(ToolNames.pubspec,
            'Unknown SDKs: ${pubspec.unknownSdks}', 'unknown-sdks'));
      }
      final package = pubspec.name;
      log.info('Package: $package ${pubspec.version}');
  
      log.info("Pub upgrade...");
      var isFlutter = pubspec.dependsOnFlutterSdk;
  