              <img src="[[item.user.picture.thumbnail]]" />
              </template>
            </data-table-column>
            <data-table-column name="First Name">
              <template>[[item.user.name.first]]</template>
            </data-table-column>
            <data-table-column name="Last Name">
              <template>[[item.user.name.last]]</template>
            </data-table-column>
          </iron-data-table>
        </template>
      </template>
    </demo-snippet>

    <h3>Header Templa