WhattsStrogatz algorithm from this site gives an error on graph command

Here, the WhattsStrogatz algorithm from this site gives an error on graph command. What goes wrong?

[John D'Errico]

Is there a good reason why you cannot tell us what error you got? Show the COMPLETE error message.

[Jan]

Undefined function or variable 'graph'.

Error in WattsStrogatz (line 26) h = graph(s,t);

I think I know the reason for this error, I do not have r2016b, I have 2015a only

[John D'Errico]

That seems a good conclusion.

Answer 1

[Walter Roberson]

graph was added in R2015b.