code: def trace2array(self, sl):
          
          chain = []
          for stochastic in self.stochastics:
              tr = stochastic.trace.gettrace(slicing=sl)
              if tr is None:
                  raise AttributeError
              chain.append(tr)
          return np.hstack(chain)
docs: Return an array with the trace of all stochastics, sliced by sl.