code: def neighbors(self, n, t=None):
          
          try:
              if t is None:
                  return list(self._adj[n])
              else:
                  return [i for i in self._adj[n] if self.__presence_test(n, i, t)]
          except KeyError:
              raise nx.NetworkXError("The node %s is not in the graph." % (n,))
docs: Return a list of the nodes connected to the node n at time t.
  
          Parameters
          ----------
          n : node
             A node in the graph
          t : snapshot id (default=None)
              If None will be returned the neighbors of the node on the flattened graph.
  
  
          Returns
          -------
          nlist : list
              A list of nodes that are adjacent to n.
  
          Raises
          ------
          NetworkXError
              If the node n is not in the graph.
  
          Examples
          --------
          >>> G = dn.DynGraph()
          >>> G.add_path([0,1,2,3], t=0)
          >>> G.neighbors(0, t=0)
          [1]
          >>> G.neighbors(0, t=1)
          []