function createNamedFunction(name, body) {       return new Function("body", "return function " + name + "() {\n" + "    \"use strict\";" + "    return body.apply(this, arguments);\n" + "};\n")(body);     };     var errorName = 'InternalError';     var errorClass = createNamedFunction(errorName, function (message) {       this.name = errorName;       this.message = message;     }); 动态方法生成问题： 以上写法再小程序中会提示 TypeError: (intermediate value) is not a function