Check If Permission Entity Exists Via API

[Paul Tiseo]

I have a ScriptRunner script that adds multiple permissions to scheme for a given user, group or role. But, if I run it twice, it adds duplicates. Is there a class/method that checks if a permission entity already exists? Also, how do I delete an entry via the API?

Here's the block that adds:

 if(permsToAdd.any({ it == prjPerm.getKey() })) {
   // add it, if not present (or we get dups)
   SchemeEntity schemeEntity = new SchemeEntity(permType, permRoleId, prjPerm.getKey())
   permSchemeMgr.createSchemeEntity(scheme, schemeEntity)
 }