anchor.diff:  // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
   // for details. All rights reserved. Use of this source code is governed by a
   // BSD-style license that can be found in the LICENSE file.
  -
  -// @dart = 2.9
   
   import 'dart:collection';
   
  
positive.code:   ///
    /// If [formals] is present, only emit the definitions which depend on the
    /// formals.
    List<js_ast.Statement> dischargeFreeTypes([Iterable<TypeParameter> formals]) {
      var decls = <js_ast.Statement>[];
      var types = formals == null
          ? typeContainer.keys.where((p) => freeTypeParameters(p).isNotEmpty)
  
negative.code:       // TODO(40273) Remove prepended text when we have a better way to hide
        // these names from debug tools.
        _unboundTypeIds[type] =
            js_ast.TemporaryId(escapeIdentifier('__t\$${_typeString(type)}')!);
      }
  
      for (var free in freeVariables) {
  