var myMixin = {
  data: function() {
    return {
      foo: 'bar',
    }
  },
  mounted: function() {
    console.log('mounted')
  }
}

var component = {
  // pass mixins
  mixins: [myMixin],

  data: function () {
    // component already have foo: 'bar' in data
    return {
      john: 'doe',
    }
  },

  // component already have mounted hook inherited from mixin
  // in addition we can add one more mounted hook
  mounted: function () {
    console.log('component mounted')
  }
}