>>> import booost.graph as bgl
>>> a=bgl.Graph.small_world_graph(5,5,.9, allow_self_loops=True)
>>> bgl.page_rank(a,a.add_vertex_property('float'))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
Boost.Python.ArgumentError: Python argument types in
    boost.graph._graph.page_rank(Graph, GraphVertexPropertyMap)
did not match C++ signature:
    page_rank(boost::graph::python::basic_graph<boost::bidirectionalS> graph, boost::vector_property_map<float, boost::graph::python::basic_index_map<boost::graph::python::basic_descriptor<void*, boost::bidirectionalS>, boost::adj_list_vertex_property_map<boost::adjacency_list<boost::listS, boost::listS, boost::bidirectionalS, boost::property<boost::vertex_index_t, unsigned int, boost::no_property>, boost::property<boost::edge_index_t, unsigned int, boost::no_property>, boost::no_property, boost::listS>, unsigned int, unsigned int const&, boost::vertex_index_t> > > {lvalue} rank_map, boost::python::api::object done_or_iterations=20, float damping=0.84999999999999998)