Replacement for current_user_has_subscription() function


I inherited a WordPress site that was originally created by another team of developers. They used the Membership plugin to control certain functionality of the site, and incorporated several plugin-specific PHP functions into the site's template in order to do so.

With the upgrade to Membership 2, at least one of those functions is not working..I'm getting an error when WordPress tries to call the current_user_has_subscription() function. Is there a replacement for this function? Also, is there any documentation of the php functions that are available for this plugin?

Thank you!