|  | // Copyright (c) 2016, 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 = 2.10 | 
|  |  | 
|  | /// Collects definitions provided to the compiler via the `-D` flag. | 
|  | /// | 
|  | /// Environment variables can be used in the user code in two ways. From | 
|  | /// conditional imports, and from `const String.fromEnvironment` and | 
|  | /// other similar constructors. | 
|  | class Environment { | 
|  | /// An immutable map of environment variables. | 
|  | final Map<String, String> definitions; | 
|  |  | 
|  | Environment(Map<String, String> definitions) | 
|  | : this.definitions = Map.unmodifiable(definitions); | 
|  | } |