title: Cannot assign to 'property' because it is a read-only property mixin
body: <p>I have mixin as below</p>
  <pre><code>export default mixins().extend({
      data() {
        return {         
          gridSchema: [] as any, } 
    }
  });
  </code></pre>
  <p>and i am using in MyComponent.vue there also i have data with same name gridSchema</p>
  <pre><code>  data(){
      return {
       defaultGridSchema: defaultGridSchema as GridSchemaEntry[],
       gridSchema: [] as GridSchemaEntry[]
     }
  }
  
  </code></pre>
  <p>In my MyComponent.vue when i write</p>
  <pre><code> this.gridSchema = this.defaultGridSchema;
  </code></pre>
  <p>it gives me error</p>
  <p><code>Cannot assign to 'gridSchema' because it is a read-only property.</code>
  Am i missing anything. Please guide me on the same.</p>