func (forest *Runtime) AddCartTree(tree cart.Runtime) {
	forest.trees = append(forest.trees, tree)
}
AddCartTree add tree to forest
package rf
import (
	"errors"
	"fmt"
	"math"
	"github.com/shuLhan/share/lib/debug"
	"github.com/shuLhan/share/lib/floats64"
	"github.com/shuLhan/share/lib/ints"
	"github.com/shuLhan/share/lib/mining/classifier"
	"github.com/shuLhan/share/lib/mining/classifier/cart"
	libstrings "github.com/shuLhan/share/lib/strings"
	"github.com/shuLhan/share/lib/tabula"
)
const (
	tag = "[rf]"
	DefNumTree = 100
	DefPercentBoot = 66
	DefOOBStatsFile = "rf.oob.stat"
	DefPerfFile = "rf.perf"
	DefStatFile = "rf.stat"
)
var (
	ErrNoInput = errors.New("rf: input samples is empty")
)
type Runtime struct {
	classifier.Runtime
	NTree int `json:"NTree"`
	NRandomFeature int `json:"NRandomFeature"`
	PercentBoot int `json:"PercentBoot"`
	nSubsample int
	trees []cart.Runtime
	bagIndices [][]int
}
func (forest *Runtime) Trees() []cart.Runtime {
	return forest.trees
}