func (p *PercentRank) Window() *sql.Window {
	return p.window
}
Window implements sql.WindowExpression
package window
import (
	"sort"
	"strings"
	"github.com/dolthub/go-mysql-server/sql/expression"
	"github.com/dolthub/go-mysql-server/sql"
)
type PercentRank struct {
	window *sql.Window
	pos    int
}
var _ sql.FunctionExpression = (*PercentRank)(nil)
var _ sql.WindowAggregation = (*PercentRank)(nil)
func NewPercentRank() sql.Expression {
	return &PercentRank{}
}