code: def guard_retract(analysis):
      
      # Cannot retract if there are dependents that cannot be retracted
      if not is_transition_allowed(analysis.getDependents(), "retract"):
          return False
  
      dependencies = analysis.getDependencies()
      if not dependencies:
          return True
  
      # Cannot retract if all dependencies have been verified
      if all(map(lambda an: IVerified.providedBy(an), dependencies)):
          return False
  
      return True
docs: Return whether the transition "retract" can be performed or not