title: How to write unit tests for child entity or child table which is extending a parent table in Nest.JS
body: <p>When I run nestjs unit tests, the below exception is occurred. Without extending it works very well, but in this case it is crashing.</p>
  <p>Test suite failed to run
  TypeError: Class extends value undefined is not a constructor or null</p>
  <ul>
  <li>Child Table</li>
  </ul>
  <pre><code>import { ParentTable } from '../../core/utils/parent.table';
  @Table({
    tableName: 'table_name',
  })
  export class ChildTable extends ParentTable&lt;ChildTable&gt;
  </code></pre>
  <ul>
  <li>Parent table</li>
  </ul>
  <pre><code>import {
    Model,
  } from 'sequelize-typescript';
  export class ParentTable&lt;T&gt; extends Model&lt;T&gt; {
  </code></pre>