How to fix row as expanded row when click first time and also when click on next time with group options in vue-good-table?

Question

I'm using vue-good-table plugin in laravel-vuejs project. I've a table and I want to display group wise row data through this option (:group-options): and now my question is how can we only expand particular parent row when click on it multiple time. we want it to only expanded but not collapse. if we load application then first time it will collapse, it's right.

  <vue-good-table
    ref="MyCoolTable"
    :columns="columns"
    :rows="rows"
    @on-row-click="toggleExpansion"
    :group-options="{
      enabled: true,
      collapsable:true
    }"
  /> 

**App Methods**
methods: {
    toggleExpansion(row,index) {

    }
}

Thank you.