protected Mac(MacSpi macSpi,Provider provider,String algorithm){
  this.spi=macSpi;
  this.provider=provider;
  this.algorithm=algorithm;
  serviceIterator=null;
  lock=null;
}

protected Mac ( MacSpi macSpi , Provider provider , String algorithm ) { this . spi = macSpi ; this . provider = provider ; this . algorithm = algorithm ; serviceIterator = null ; lock = null ; }
creates a mac object .
