code: func (t *partitionedTable) GetPartitionByRow(ctx sessionctx.Context, r []types.Datum) (table.Table, error) {
  	pid, err := t.locatePartition(ctx, t.Meta().GetPartitionInfo(), r)
  	if err != nil {
  		return nil, errors.Trace(err)
  	}
  	return t.partitions[pid], nil
  }
docs: // GetPartitionByRow returns a Table, which is actually a Partition.