func (ss *StrategyStat) Reset() {
	ss.accSize = 0
	ss.firstBegin = nil
	ss.lastEnd = time.Unix(0, 0)
}
Reset resets the counters associated with a specfiic `StrategyStat` object
package session
import (
	"bytes"
	"sync"
	"time"
	kb "github.com/lsds/KungFu/srcs/go/kungfu/base"
	"github.com/lsds/KungFu/srcs/go/plan"
	"github.com/lsds/KungFu/srcs/go/plan/graph"
	"github.com/lsds/KungFu/srcs/go/plan/subgraph"
	"github.com/lsds/KungFu/srcs/go/utils/assert"
)
type StrategyStatSnapshot struct {
	Throughput float64
}
type StrategyStat struct {
	Throughput float64
	accSize    int
	firstBegin *time.Time
	lastEnd    time.Time
	reff       StrategyStatSnapshot
	lock       sync.Mutex
}
func (ss *StrategyStat) GetSnapshot() StrategyStatSnapshot {
	return StrategyStatSnapshot{Throughput: ss.Throughput}
}