code: def use_step_method(self, step_method_class, *args, **kwds):
          
  
          new_method = step_method_class(*args, **kwds)
          if self.verbose > 1:
              print_(
                  'Using step method %s. Stochastics: ' %
                  step_method_class.__name__)
  
          for s in new_method.stochastics:
              self.step_method_dict[s].append(new_method)
              if self.verbose > 1:
                  print_('\t' + s.__name__)
          if self._sm_assigned:
              self.step_methods.add(new_method)
  
          setattr(new_method, '_model', self)
docs: M.use_step_method(step_method_class, *args, **kwds)
  
          Example of usage: To handle stochastic A with a Metropolis instance,
  
              M.use_step_method(Metropolis, A, sig=.1)
  
          To subsequently get a reference to the new step method,
  
              S = M.step_method_dict[A][0]