How to traverse through the drop down list using Unstoppable

Step 1 The user can navigate through the drop down lists using the TAB key of the keyboard.

Step 2 The User can expand and collapse the drop down list using the SPACE key of the keyboard.

Step 3 The User can focus on expanded drop down list by using the INSERT+CTRL+M keys of the keyboard.

Step 4 The User can navigate through the drop down list by using the UP/DOWN arrow keys of the keyboard.

Step 5 The User can  select the value in drop down by using the ENTER key of the keyboard.