r.SchedWaitTime -= v.SchedWaitTime
	for reason := range s.BlockTimeByReason {
		r.BlockTimeByReason[reason] -= v.BlockTimeByReason[reason]
	}
	r.SyscallTime -= v.SyscallTime
	r.SyscallBlockTime -= v.SyscallBlockTime
	r.TotalTime -= v.TotalTime
	for name := range s.RangeTime {
		r.RangeTime[name] -= v.RangeTime[name]
	}
	return r
}

func (s GoroutineExecStats) clone() (r GoroutineExecStats) {

	}
	if stats.SchedWaitTime < 0 {
		t.Error("found negative SchedWaitTime")
	}
	if stats.SyscallTime < 0 {
		t.Error("found negative SyscallTime")
	}
	if stats.SyscallBlockTime < 0 {
		t.Error("found negative SyscallBlockTime")
	}
	if stats.TotalTime < 0 {
		t.Error("found negative TotalTime")
	}
	for reason, dt := range stats.BlockTimeByReason {
		if dt < 0 {