code: def log_prior(self):
          
          for p, b in zip(self.parameter_vector, self.parameter_bounds):
              if b[0] is not None and p < b[0]:
                  return -np.inf
              if b[1] is not None and p > b[1]:
                  return -np.inf
          return 0.0
docs: Compute the log prior probability of the current parameters