code: func MockPartitionInfoSchema(definitions []model.PartitionDefinition) infoschema.InfoSchema {
  	tableInfo := *MockTable()
  	cols := make([]*model.ColumnInfo, 0, len(tableInfo.Columns))
  	cols = append(cols, tableInfo.Columns...)
  	cols = append(cols, &model.ColumnInfo{
  		State:     model.StatePublic,
  		Offset:    10,
  		Name:      model.NewCIStr("h"),
  		FieldType: newLongType(),
  		ID:        11,
  	})
  	partition := &model.PartitionInfo{
  		Type:        model.PartitionTypeRange,
  		Expr:        "h",
  		Enable:      true,
  		Definitions: definitions,
  	}
  	tableInfo.Columns = cols
  	tableInfo.Partition = partition
  	is := infoschema.MockInfoSchema([]*model.TableInfo{&tableInfo})
  	return is
  }
docs: // MockPartitionInfoSchema mocks an info schema for partition table.