fn init_investment_graph(
graph: &CommoditiesGraph,
commodities: &CommodityMap,
) -> Graph<MarketSet, GraphEdge, Directed>Expand description
Initialise an InvestmentGraph from a CommoditiesGraph.
The commodity graph is filtered to only include SVD/SED commodity nodes. Each commodity node
(carrying both CommodityID and RegionID) is added to the investment graph as a
MarketSet::Single, with edges preserved.