[
  {
    text: 'Kyiv',
    country: 'Ukraine'
  },
  {
    text: 'Warsaw',
    country: 'Poland'
  },
  {
    text: 'Munich',
    country: 'Germany'
  },
  {
    text: 'Milan',
    country: 'Italy'
  },
  {
    text: 'Barcelona', 
    country: 'Spain'
  }
]
                      

                        
Vue.component('custom-delegate', {
  props: {
    data: {},

    field: {}
  },

  template: '<div>' +
              '<span v-html="data[field]"></span>' +
              '<br>' +
              '<span style="color: #ccc">{{ data.country }}</span>' +
            '</div>'
})
                        
                      

                        
filterResults(data) {
  if(!data || !data.items)
    return

  return data.items.map(function(item) {
    item.text = item.volumeInfo.title
    return item
  })
}