public HeldLocksGrant refresh(long expirationDateMs){
  return new HeldLocksGrant(grantId,creationDateMs,expirationDateMs,lockMap,lockTimeout,versionId);
}

public HeldLocksGrant refresh ( long expirationDateMs ) { return new HeldLocksGrant ( grantId , creationDateMs , expirationDateMs , lockMap , lockTimeout , versionId ) ; }
this should only be called by the lock service . calling this method won ' t actually refresh the grant .
