code: func InstantiatePurgeMgr(ledgerid string, db privacyenabledstate.DB, btlPolicy pvtdatapolicy.BTLPolicy, bookkeepingProvider bookkeeping.Provider) (PurgeMgr, error) {
  	return &purgeMgr{
  		btlPolicy: btlPolicy,
  		db:        db,
  		expKeeper: newExpiryKeeper(ledgerid, bookkeepingProvider),
  		lock:      &sync.Mutex{},
  		waitGrp:   &sync.WaitGroup{},
  	}, nil
  }
docs: // InstantiatePurgeMgr instantiates a PurgeMgr.