code: def gettrace(self, burn=0, thin=1, chain=-1, slicing=None):
          
          if slicing is None:
              slicing = slice(burn, None, thin)
          if chain is not None:
              if chain < 0:
                  chain = range(self.db.chains)[chain]
              return self._trace[chain][slicing]
          else:
              return concatenate(list(self._trace.values()))[slicing]
docs: Return the trace.
  
          :Stochastics:
            - burn (int): The number of transient steps to skip.
            - thin (int): Keep one in thin.
            - chain (int): The index of the chain to fetch. If None, return all chains.
            - slicing: A slice, overriding burn and thin assignement.