code: def _add_services(self, this_service, other_services):
          
          if this_service['name'] != os.path.basename(os.getcwd()):
              s = this_service['name']
              msg = "The charm's root directory name needs to be {}".format(s)
              amulet.raise_status(amulet.FAIL, msg=msg)
  
          if 'units' not in this_service:
              this_service['units'] = 1
  
          self.d.add(this_service['name'], units=this_service['units'],
                     constraints=this_service.get('constraints'),
                     storage=this_service.get('storage'))
  
          for svc in other_services:
              if 'location' in svc:
                  branch_location = svc['location']
              elif self.series:
                  branch_location = 'cs:{}/{}'.format(self.series, svc['name']),
              else:
                  branch_location = None
  
              if 'units' not in svc:
                  svc['units'] = 1
  
              self.d.add(svc['name'], charm=branch_location, units=svc['units'],
                         constraints=svc.get('constraints'),
                         storage=svc.get('storage'))
docs: Add services.
  
             Add services to the deployment where this_service is the local charm
             that we're testing and other_services are the other services that
             are being used in the local amulet tests.