docs: def register(self, sim, *args, **kwargs):
          """
          register simulation and metadata.
  
          * ``commands`` - list of methods to callable from model
  
          :param sim: new simulation
          """
          kwargs.update(zip(self.meta_names, args))
          # call super method, now meta can be passed as args or kwargs.
          super(SimRegistry, self).register(sim, **kwargs)