title: How to add custom drop down filter in wordpress WP_List_Table
body: <p>I extended class <code>WP_List_Table</code> to display listing records of Custom Database Table. Listing is successful but I'm getting mad about how to implement a drop-down filter to filter my custom db table records according to its categories.</p>
  
  <p>Please share any code to add drop-down filter to filter my custom database table records. Field name is <code>cat_id</code>.</p>