func (neighbors *Neighbors) Distance(idx int) float64 {
	return neighbors.distances[idx]
}
Distance return distance value at index `idx`.
package knn
import (
	"github.com/shuLhan/share/lib/tabula"
)
type Neighbors struct {
	rows []*tabula.Row
	distances []float64
}
func (neighbors *Neighbors) Rows() *[]*tabula.Row {
	return &neighbors.rows
}
func (neighbors *Neighbors) Row(idx int) *tabula.Row {
	return neighbors.rows[idx]
}
func (neighbors *Neighbors) Distances() *[]float64 {
	return &neighbors.distances
}