Converted Observatory field-view element

runtime/observatory/lib/src/models/objects/field.dart

 // 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
 
 part of models;
 
 abstract class FieldRef extends ObjectRef {
   /// The name of this field.
   String get name;
 
   /// The owner of this field, which can be either a Library or a
   /// Class.
   ObjectRef get dartOwner;
 
   /// The declared type of this field.
   ///
   /// The value will always be of one of the kinds:
   /// Type, TypeRef, TypeParameter, BoundedType.
   InstanceRef get declaredType;
 
   /// Is this field const?
   bool get isConst;
 
   /// Is this field final?
   bool get isFinal;
 
   /// Is this field static?
   bool get isStatic;
 }
+
+enum GuardClassKind {
+  unknown,
+  single,
+  dynamic
+}
+
+abstract class Field extends Object implements FieldRef {
+  /// [optional] The value of this field, if the field is static.
+  InstanceRef get staticValue;
+
+  /// [optional] The location of this field in the source code.
+  SourceLocation get location;
+
+  GuardClassKind get guardClassKind;
+  ClassRef get guardClass;
+  bool get guardNullable;
+}