# File lib/symetrie_com/acts_as_better_nested_set.rb, line 562
        def level(scope = {})
          return 0 if self[parent_col_name].nil?
          self.class.count_in_nested_set({ :conditions => "#{scope_condition} AND (#{self[left_col_name]} BETWEEN #{prefixed_left_col_name} AND #{prefixed_right_col_name})" }, scope) - 1
        end