code: func (f *freeClientPool) logOffset(now mclock.AbsTime) int64 {
  	// Note: fixedPointMultiplier acts as a multiplier here; the reason for dividing the divisor
  	// is to avoid int64 overflow. We assume that int64(recentUsageExpTC) >> fixedPointMultiplier.
  	logDecay := int64((time.Duration(now - f.startupTime)) / (recentUsageExpTC / fixedPointMultiplier))
  	return f.logOffsetAtStartup + logDecay
  }
docs: // logOffset calculates the time-dependent offset for the logarithmic
  // representation of recent usage