Basically, the thing is I have 4 expansion panel and I want the first panel should be open or expanded by default and when I click on the second panel the first one should be close.

In vuetify doc they have both the eg. one for how to by default open the panel and second is, when one should open others should be closed. 

```
<template>
  <div>
 <div class="text-xs-center mb-3">{{ panel }}</div>    
 <v-expansion-panel
  expand
  v-model="panel">
  <v-expansion-panel-content
    v-for="(details,index) in marketCapDetails"
    :key="index">
    <template v-slot:header>
       <p>{{details.sr_no }}</p>
       <p>{{details.currency }}</p>
    </template>
    <v-card>
      #some code
    </v-card>      
  </v-expansion-panel-content>
</v-expansion-panel>

```

and in my script

```
export default {   
  data() {
    return {
            panel:[true, false, false, false]
         }   
      }
}

```