code: def out_degree(self, nbunch=None, t=None):
          
          if nbunch in self:  # return a single node
              return next(self.out_degree_iter(nbunch, t))[1]
          else:  # return a dict
              return dict(self.out_degree_iter(nbunch, t))
docs: Return the out degree of a node or nodes at time t.
  
          The node degree is the number of interaction outgoing from that node in a given time frame.
  
          Parameters
          ----------
          nbunch : iterable container, optional (default=all nodes)
              A container of nodes.  The container will be iterated
              through once.
  
          t : snapshot id (default=None)
              If None will be returned the degree of nodes on the flattened graph.
  
  
          Returns
          -------
          nd : dictionary, or number
              A dictionary with nodes as keys and degree as values or
              a number if a single node is specified.
  
          Examples
          --------
          >>> G = dn.DynDiGraph()
          >>> G.add_interactions(0,1, t=0)
          >>> G.add_interactions(1,2, t=0)
          >>> G.add_interactions(2,3, t=0)
          >>> G.out_degree(0, t=0)
          1
          >>> G.out_degree([0,1], t=1)
          {0: 0, 1: 0}
          >>> list(G.out_degree([0,1], t=0).values())
          [1, 2]