code: def undelete_model_genes(cobra_model):
      
  
      if cobra_model._trimmed_genes is not None:
          for x in cobra_model._trimmed_genes:
              x.functional = True
  
      if cobra_model._trimmed_reactions is not None:
          for the_reaction, (lower_bound, upper_bound) in \
                  cobra_model._trimmed_reactions.items():
              the_reaction.lower_bound = lower_bound
              the_reaction.upper_bound = upper_bound
  
      cobra_model._trimmed_genes = []
      cobra_model._trimmed_reactions = {}
      cobra_model._trimmed = False
docs: Undoes the effects of a call to delete_model_genes in place.
  
      cobra_model:  A cobra.Model which will be modified in place