# Group (i.e. subgraph) + Edge + Group. OK.
(cluster_1: [Solar system]->{arrowhead: diamond}[Earth]){bgcolor: cornflowerblue; label: Locale}
->
(cluster_2: [Australia] -> [Victoria] -> [Melbourne] -> [Murrumbeena]){bgcolor: lightblue; label: Home}
# Group (i.e. subgraph) + Edge + Group. OK.
(cluster_1: [Solar system]->{arrowhead: diamond}[Earth]){bgcolor: cornflowerblue; label: Locale}
->
(cluster_2: [Australia] -> [Victoria] -> [Melbourne] -> [Murrumbeena]){bgcolor: lightblue; label: Home}