GenerateUniqueRoleID returns the next available Role ID and increments the counter.

GenerateUniqueRoleIDInTxn is like GenerateUniqueRoleID but performs the operation in the provided transaction.

IncrementUniqueRoleID returns the next available Role ID and increments the counter by inc.

NewGenerator constructs a non-transactional eval.DescIDGenerator.

NewTransactionalGenerator constructs a transactional eval.DescIDGenerator.