code: def grant_bonus(self, worker_id, assignment_id, bonus_price, reason):
          
          params = bonus_price.get_as_params('BonusAmount', 1)
          params['WorkerId'] = worker_id
          params['AssignmentId'] = assignment_id
          params['Reason'] = reason
  
          return self._process_request('GrantBonus', params)
docs: Issues a payment of money from your account to a Worker.  To
          be eligible for a bonus, the Worker must have submitted
          results for one of your HITs, and have had those results
          approved or rejected. This payment happens separately from the
          reward you pay to the Worker when you approve the Worker's
          assignment.  The Bonus must be passed in as an instance of the
          Price object.