vue-promise-btn

<template>
    <div>
        <button class="btn btn-success" @click="save" v-promise-btn>Working</button>
        <button class="btn btn-success" @click="save()" v-promise-btn>Not working</button>
    </div>
</template>

<script>
    import Vue from 'vue';
    import VuePromiseBtn from 'vue-promise-btn';
    import 'vue-promise-btn/dist/vue-promise-btn.css';

    Vue.use(VuePromiseBtn);

    export default {
        methods: {
            save() {
                return new Promise((resolve, reject) => {

                });
            }
        }
    }
</script>