code: def list_scans(self, source_id=None):
          
          if source_id:
              target_url = self.client.get_url('SCAN', 'GET', 'multi', {'source_id': source_id})
          else:
              target_url = self.client.get_ulr('SCAN', 'GET', 'all')
          return base.Query(self.client.get_manager(Scan), target_url)
docs: Filterable list of Scans for a Source.
          Ordered newest to oldest by default