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yaml/lib/src/utils.dart

-// Copyright (c) 2013, 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.
-
-library yaml.utils;
-
-import 'package:source_span/source_span.dart';
-
-/// A pair of values.
-class Pair<E, F> {
-  final E first;
-  final F last;
-
-  Pair(this.first, this.last);
-
-  String toString() => '($first, $last)';
-}
-
-/// Print a warning.
-///
-/// If [span] is passed, associates the warning with that span.
-void warn(String message, [SourceSpan span]) =>
-    yamlWarningCallback(message, span);
-
-/// A callback for emitting a warning.
-///
-/// [message] is the text of the warning. If [span] is passed, it's the portion
-/// of the document that the warning is associated with and should be included
-/// in the printed warning.
-typedef YamlWarningCallback(String message, [SourceSpan span]);
-
-/// A callback for emitting a warning.
-///
-/// In a very few cases, the YAML spec indicates that an implementation should
-/// emit a warning. To do so, it calls this callback. The default implementation
-/// prints a message using [print].
-YamlWarningCallback yamlWarningCallback = (message, [span]) {
-  // TODO(nweiz): Print to stderr with color when issue 6943 is fixed and
-  // dart:io is available.
-  if (span != null) message = span.message(message);
-  print(message);
-};
-
-