code: def get_minimal_fba_flux(self, objective):
          
          # Define constraints
          vs_wt = self._v_wt.set(self._model.reactions)
          zs = self._z.set(self._model.reactions)
  
          wt_obj_flux = self.get_fba_obj_flux(objective)
  
          with self.constraints() as constr:
              constr.add(
                  zs >= vs_wt, vs_wt >= -zs,
                  self._v_wt[objective] >= wt_obj_flux)
              self._prob.set_objective(self._z.sum(self._model.reactions))
              result = self._solve(lp.ObjectiveSense.Minimize)
  
          fba_fluxes = {}
          for key in self._model.reactions:
              fba_fluxes[key] = result.get_value(self._v_wt[key])
          return fba_fluxes
docs: Find the FBA solution that minimizes all the flux values.
  
          Maximize the objective flux then minimize all other fluxes
          while keeping the objective flux at the maximum.
  
          Args:
              objective: The objective reaction that is maximized.
  
          Returns:
              A dictionary of all the reactions and their minimized fluxes.