anchor.diff:    /// functions referenced within `get-function` calls (those nodes instead
     /// map to the [ReferenceSource] for the `sass:meta` module).
     final Map<SassNode, ReferenceSource> sources;
  +
  +  /// The importers that were used to load each canonical URL.
  +  ///
  +  /// If a URL is loaded multiple times through different importers, this
  +  /// contains only the first importer.
  +  ///
  +  /// This isn't necessarily the same as the importer that would be returned by
  +  /// [ImportCache.import]. For URLs that multiple importers canonicalize into
  +  /// the same format (like `file:` URLs), the [ImportCache] will use the first
  +  /// importer that recognizes the canonical format, whereas this tracks the
  +  /// importer that originally loaded the URL from its non-canonical form.
  +  final Map<Uri, Importer> importers;
   
     /// An iterable of all member declarations.
     Iterable<MemberDeclaration> get allDeclarations =>
  
positive.code:       BidirectionalMap<FunctionExpression, MemberDeclaration<FunctionRule>>();
    final _globalDeclarations = <MemberDeclaration>{};
    final _sources = <SassNode, ReferenceSource>{};
  
    /// The current global scope.
    ///
  
negative.code: import '../../util/bidirectional_map.dart';
  import '../../util/unmodifiable_bidirectional_map_view.dart';
  import '../../utils.dart';
  import 'built_in_functions.dart';
  import 'member_declaration.dart';
  import 'reference_source.dart';
  import 'scope.dart';
  
  