Comment #11 on issue 113 by tudor.gi...(a)gmail.com: Roassal should support
lazy edges when used through the Mondrian API
http://code.google.com/p/moose-technology/issues/detail?id=113
furthermore, this should work as well:
edge := view edge: #edge from: 1 to: 2.
view edge: #edge from: 2 to: 1.
view node: 1.
view node: 2.
view treeLayout userDefinedEdges: {edge}
This was achieved in the original Mondrian by having a Future object
implementation.