public ExportNamedDeclaration(StatementListItem declaration, List <ExportSpecifier> specifiers, Literal source)
 {
     Type        = Nodes.ExportNamedDeclaration;
     Declaration = declaration;
     Specifiers  = specifiers;
     Source      = source;
 }
        public readonly StatementListItem Declaration; //: BindingIdentifier | BindingPattern | ClassDeclaration | Expression | FunctionDeclaration;

        public ExportDefaultDeclaration(StatementListItem declaration) : base(Nodes.ExportDefaultDeclaration)
        {
            Declaration = declaration;
        }