Contracting Vertices in graph_tool

Question

I'm trying to switch over from using networkx to graph_tool for python, however there doesn't seem to be a feature in graph_tool to contract nodes. For the purposes of my graph this is also equivalent to edge contraction. Does anyone know if such a feature exists in graph_tool or how I could implement it? My main concern about implementing it in python is if it slows down considerably such that the switch from networkx to graph_tool may not have been worth it.