code: def list(self, mask=None):
          
          if mask is None:
              mask = "mask[id, name, createDate, rule, guestCount, backendRouter[id, hostname]]"
          groups = self.client.call('Account', 'getPlacementGroups', mask=mask, iter=True)
          return groups
docs: List existing placement groups
  
          Calls SoftLayer_Account::getPlacementGroups