Some more test for sortLayer
Some more test for sortLayer

GerHobbelt/dagre,cpettitt/dagre,lmcorbo/dagre,cpettitt/dagre,9n/dagre,lmcorbo/dagre,9n/dagre,witcxc/dagre,kdawes/dagre,tylingsoft/dagre-layout,lmcorbo/dagre,cpettitt/dagre,kdawes/dagre,GerHobbelt/dagre,kdawes/dagre,shelsonjava/dagre,abduld/dagre,tylingsoft/dagre-layout,shelsonjava/dagre,shelsonjava/dagre,9n/dagre,abduld/dagre,witcxc/dagre,rwl/dagre,GerHobbelt/dagre,abduld/dagre