[graph-tool] choose version of graphtool

Hello Tiago, I am wondering can I choose the version of graphtool library. I have now the version 2.29 and my colleague has an older one 2.27. Can I install version 2.27? I save a block state created with 2.29 as .pkl and he can not open it with 2.27 and got an error: "AttributeError: Can't get attribute 'VertexPropertyMap' on <module 'graph_tool' from '/usr/lib/python3/dist-packages/graph_tool/__init__.py'>" Best regards -- Sent from: http://main-discussion-list-for-the-graph-tool-project.982480.n3.nabble.com/