graph ethane {}
digraph foo {}
subgraph bar {}

----------------------------------------------------

[
	["keyword", "graph"],
	["graph-name", ["ethane"]],
	["punctuation", "{"],
	["punctuation", "}"],

	["keyword", "digraph"],
	["graph-name", ["foo"]],
	["punctuation", "{"],
	["punctuation", "}"],

	["keyword", "subgraph"],
	["graph-name", ["bar"]],
	["punctuation", "{"],
	["punctuation", "}"]
]