Usage of column type "expand"

[dem3trio]

Hello, I'm trying to guess how to use the column type "expand".

When I use it, I'm getting the arrow, and it is expanding an empty row, but I cannot set nothing into that expanded element.

Searching in the code I've seen this:

        ........
       v-if="column.type === undefined">
          <template slot-scope="scope" :scope="newSlotScope ? 'scope' : false">
            <span v-if="column.filter">
              {{ Vue.filter(column['filter'])(scope.row[column.prop]) }}
            </span>
            <span v-else-if="column.slotName">
              <slot :name="column.slotName" :row="scope.row" :$index="scope.$index" />
            </span>
            <span v-else-if="column.render">
              {{ column.render(scope.row) }}
            </span>
            <span v-else-if="column.formatter">
              {{ column.formatter(scope.row, scope.column, scope.row[column.prop], scope.$index) }}
            </span>
            <span v-else>
              {{ scope.row[column.prop] }}
            </span>
          </template>
        </el-table-column>
        <el-table-column v-bind="column" :key="columnIndex" v-else></el-table-column>

When the type is "expand" it uses the last line, so it seems that It's impossible to set the expanded row template inside of the el-table-column tag

Is there any way to use this functionality or it is not fully supported?

Thanks in advance.