anchor.diff:  
   import 'package.dart';
   import 'source.dart';
  +import 'source/git.dart';
   import 'source/hosted.dart';
  +import 'source/path.dart';
   import 'utils.dart';
   
   /// The equality to use when comparing the feature sets of two package names.
  
positive.code:     if (isMagic) return name;
  
      var buffer = new StringBuffer(name);
      if (detail.showVersion ?? true) buffer.write(" $constraint");
  
      if (detail.showSource ?? source is! HostedSource) {
        buffer.write(" from $source");
  
negative.code:   /// Whether to show the package version or version range.
    ///
    /// If this is `null`, the version is shown for all packages other than root
    /// [PackageId]s or [PackageRange]s with `git` or `path` sources and `any`
    /// constraints.
    final bool showVersion;
  
    /// Whether to show the package source.
  