# File lib/aws/record/abstract_base.rb, line 315
        def opt_lock_conditions
          conditions = {}
          if_locks_optimistically do |lock_attr|
            if was = attribute_was(lock_attr.name)
              conditions[:if] = { lock_attr.name => lock_attr.serialize(was) }
            else
              conditions[:unless_exists] = lock_attr.name
            end
          end
          conditions
        end