-- If iterative coalescing is enabled, the scanner will coalesce the graph as does its business.
-- We need to apply all the coalescences found by the scanner to the original
-- graph before doing assignColors.
-- If iterative coalescing is enabled, the scanner will coalesce the graph as does its business.
-- We need to apply all the coalescences found by the scanner to the original
-- graph before doing assignColors.
-- color the trivially colorable nodes
-- during scanning, keys of triv nodes were added to the front of the list as they were found
-- color the trivially colorable nodes
-- during scanning, keys of triv nodes were added to the front of the list as they were found