Strong html

tools/dom/src/CssClassSet.dart

Index: tools/dom/src/CssClassSet.dart
diff --git a/tools/dom/src/CssClassSet.dart b/tools/dom/src/CssClassSet.dart
index 8224b77d538c94dfe9f16e43032814a8a250bb2b..d2334a7b350bababd99ccb921b976328598dc8fd 100644
--- a/tools/dom/src/CssClassSet.dart
+++ b/tools/dom/src/CssClassSet.dart
@@ -41,7 +41,7 @@ abstract class CssClassSet implements Set<String> {
    * [value] must be a valid 'token' representing a single class, i.e. a
    * non-empty string containing no whitespace.
    */
-  bool contains(String value);
+  bool contains(Object value);
 
   /**
    * Add the class [value] to element.
@@ -93,7 +93,7 @@ abstract class CssClassSet implements Set<String> {
    * Each element of [iterable] must be a valid 'token' representing a single
    * class, i.e. a non-empty string containing no whitespace.
    */
-  void removeAll(Iterable<String> iterable);
+  void removeAll(Iterable<Object> iterable);
 
   /**
    * Toggles all classes specified in [iterable] on element.