Return the star graph
The star graph consists of one center node connected to n outer nodes.
n (int or iterable) – If an integer, node labels are 0 to n with center 0. If an iterable of nodes, the center is the first.
create_using (NetworkX graph constructor, optional (default=nx.Graph)) – Graph type to create. If graph instance, then cleared before populated.
The graph has n+1 nodes for integer n. So star_graph(3) is the same as star_graph(range(4)).