anchor.diff:    GraphQLType<Value, String> coerceToInputObject() => this;
   }
   
  +/// A known value of a [GraphQLEnumType].
  +///
  +/// In practice, you might not directly call this constructor very often.
   class GraphQLEnumValue<Value> {
  +  /// The name of this value.
     final String name;
  +
  +  /// The Dart value associated with enum values bearing the given [name].
     final Value value;
  +
  +  /// An optional description of this value; useful for tools like GraphiQL.
     final String description;
  +
  +  /// The reason, if any, that this value was deprecated, if it indeed is deprecated.
     final String deprecationReason;
   
     GraphQLEnumValue(this.name, this.value,
         {this.description, this.deprecationReason});
   
  +  /// Returns `true` if this value has a [deprecationReason].
     bool get isDeprecated => deprecationReason != null;
   
     @override
  
positive.code:       description: description);
  }
  
  class GraphQLEnumType<Value> extends GraphQLScalarType<Value, String>
      with _NonNullableMixin<Value, String> {
    final String name;
    final List<GraphQLEnumValue<Value>> values;
    final String description;
  
    GraphQLEnumType(this.name, this.values, {this.description});
  
negative.code:       description: description);
  }
  
  /// Shorthand for building a [GraphQLEnumType] where all the possible values
  /// are mapped to Dart strings.
  GraphQLEnumType enumTypeFromStrings(String name, List<String> values,
      {String description}) {
    return new GraphQLEnumType<String>(
  