code: def add_star(self, nodes, t=None):
          
          nlist = list(nodes)
          v = nlist[0]
          interaction = ((v, n) for n in nlist[1:])
          self.add_interactions_from(interaction, t)
docs: Add a star at time t.
  
          The first node in nodes is the middle of the star.  It is connected
          to all other nodes.
  
          Parameters
          ----------
          nodes : iterable container
              A container of nodes.
          t : snapshot id (default=None)
  
          See Also
          --------
          add_path, add_cycle
  
          Examples
          --------
          >>> G = dn.DynGraph()
          >>> G.add_star([0,1,2,3], t=0)