Strict only applies to Digraphs

[etherealmachine]

Is it intended that the strict option only applies to Digraphs? See https://github.com/glejeune/Ruby-Graphviz/blob/c3be805fc5e62ea1326eb9bb3708a807d1178525/lib/graphviz.rb#L522.

The docs at https://graphviz.org/doc/info/lang.html seem to suggest that strict graph is also valid.