rted: Boolean,
        status: {
          type: Object,
          observer: '_statusChanged',
        },
      },

      submit() {
        // TODO: After Polymer 2.0, use:
        // this.shadowRoot.getElementById('migrate_form').submit();
        Polymer.dom(this.root).querySelector('#migrate_form').submit();
      },

      handleResponse(event) {
        this.status = event.detail.response;
      },

      duration(startTime) {
        const created = new Date(startTime + 'Z');
        const updated = 