How to add the custom authorization headers for swagger UI 3.x

Currently i am using the below snippet to add custom authorization headers for swagger ui.

 

window.authorizations.add("Content-Type", new ApiKeyAuthorization("Content-Type", "application/json", "header"));
window.authorizations.add("Version", new ApiKeyAuthorization("Version", "2", "header"));

 

Now as part of 3.x i want to use the same kind functionality available in swagger 2.x for adding the custom authorization header, i am using separate js file for adding custom authorization header based on user events.let me know how to take care of the migration.