,
                validate:RED.validators.typedInput("propertyType", false)
            },
            propertyType: { value:"msg"},
            key: {value:"topic", validate: (function () {
                const typeValidator = RED.validators.typedInput({ type: 'msg' })
                return function(v, opt) {
                    const joinMode = $("#node-input-mode").val() || this.mode
                    if (joinMode !== 'custom') {
                        return true
                    }
             