code: def _get_samples(n, sim, inc_warmup=True):
      # NOTE: this is in stanfit-class.R in RStan (rather than misc.R)
      
      return pystan._misc.get_samples(n, sim, inc_warmup)
docs: Get chains for `n`th parameter.
  
      Parameters
      ----------
      n : int
      sim : dict
          A dictionary tied to a StanFit4Model instance.
  
      Returns
      -------
      chains : list of array
          Each chain is an element in the list.