docs: def update_nodes(nodes,**kwargs):
      """
      Update multiple nodes.
      If new attributes are present, they will be added to the node.
      The non-presence of attributes does not remove them.
  
      %TODO:merge this with the 'update_nodes' functionality in the 'update_netework'
      function, so we're not duplicating functionality. D.R.Y!
  
      returns: a list of updated nodes
      """
      user_id = kwargs.get('user_id')
      updated_nodes = []
      for n in nodes:
          updated_node_i = update_node(n, flush=False, user_id=user_id)
          updated_nodes.append(updated_node_i)
  
      db.DBSession.flush()
  
      return updated_nodes