code: def lower(self):
          '''Lower bound'''
          try:
              return self._model._limits_lower[self._reaction]
          except KeyError:
              if self._model.is_reversible(self._reaction):
                  return -self._model._v_max
              else:
                  return f lower(self):
          '''Lower bound'''
          try:
              return self._model._limits_lower[self._reaction]
          except KeyError:
              if self._model.is_reversible(self._reaction):
                  return -self._model._v_max
              else:
                  return 0
docs: Lower bound