[boost] [BGL] Is it a doc error?

Hello, In the BGL doc @ http://www.boost.org/libs/graph/doc/graph_coloring.html There's a function with name 'smallest_last_ordering', in which there's a line of code: degree_buckets.push(*v); but I cannot find where is 'degree_buckets' declared. What's wrong? By the way, is there any sample code that is using this function? Thanks Max