Null graph:
( )
Empty graph:
( NaN NaN NaN NaN NaN )
Graph with 4 nodes and 5 edges:
( 0.970951 0.75 0.69137 1 )
Tree (having degree-one vertices):
( 0.918296 0.88686 0.921463 0.934206 0.890492 0 0 0 0 0 )
