code: func (p PhysicalMaxOneRow) Init(ctx sessionctx.Context, stats *property.StatsInfo, props ...*property.PhysicalProperty) *PhysicalMaxOneRow {
  	p.basePhysicalPlan = newBasePhysicalPlan(ctx, TypeMaxOneRow, &p)
  	p.childrenReqProps = props
  	p.stats = stats
  	return &p
  }
docs: // Init initializes PhysicalMaxOneRow.