docs: def _get_snapshot(vm, snapshot_name):
          """
          Returns snapshot object by its name
          :param vm:
          :param snapshot_name:
          :type snapshot_name: str
          :return: Snapshot by its name
          :rtype vim.vm.Snapshot
          """
          snapshots = SnapshotRetriever.get_vm_snapshots(vm)
  
          if snapshot_name not in snapshots:
              raise SnapshotNotFoundException('Snapshot {0} was not found'.format(snapshot_name))
  
          return snapshots[snapshot_name]