def recalculate_nested_set(left) #:nodoc:
      child_left = left + 1
      children.each do |child|
        child_left = child.recalculate_nested_set(child_left)
      end
      set_boundaries(left, child_left)
      save_without_validation!
      
      right + 1
    end
def recalculate_nested_set(left) #:nodoc:
      child_left = left + 1
      children.each do |child|
        child_left = child.recalculate_nested_set(child_left)
      end
      set_boundaries(left, child_left)
      save_without_validation!
      
      right + 1
    end
Rebuild this node's childrens boundaries