// add/remove アクセサーを明示的に書く版
        // public event EventHandler Moved
        // {
        //     add {}
        //     remove {}
        // }
        public override void VisitEventDeclaration(EventDeclarationSyntax node)
        {
            var defineType = node.ChildNodes().FirstOrDefault(x => x is IdentifierNameSyntax).ToString();
            var defineName = node.ChildTokens().FirstOrDefault(x => x.Kind() == SyntaxKind.IdentifierToken).ToString();

            var startLength     = node.Span.Start;
            var endLength       = node.Span.End;
            var parentNamespace = GetNamespace(DefineKinds.Event, startLength, endLength);

            UserDefinitions.Add(new UserDefinition
            {
                DefineKinds    = DefineKinds.Event,
                Namespace      = parentNamespace,
                DefineName     = defineName,
                DefineFullName = $"{parentNamespace}.{defineName}",
                ReturnType     = RemoveNamespace(defineType),
                SourceFile     = SourceFile,
                StartLength    = startLength,
                EndLength      = endLength,
            });

            base.VisitEventDeclaration(node);
        }