No vertices:
( )

One vertex:
( NaN )

Line graph, 4 vertices:
( 1 0.5 0.5 1 )

Full graph, 4 vertices, weights make it a line:
( 1.25 0.5625 0.5625 1.25 )

Full graph, 4 vertices, all same weights:
( 0.925926 0.925926 0.925926 0.925926 )

Full graph, 4 vertices, all same weights, but split over multiple edges:
( 0.925926 0.925926 0.925926 0.925926 )

Full graph, 4 vertices, no weights:
( 0.925926 0.925926 0.925926 0.925926 )

Full graph, 4 vertices, no weights, with loop:
( 0.925926 0.925926 0.925926 0.925926 )

Hole in middle of two clusters:
( 0.865741 0.865741 0.865741 0.583333 0.5 0.583333 0.865741 0.865741 0.865741 )