public KeyStoreBuilder withProvider(final String providerName){
  Provider provider=Security.getProvider(providerName);
  if (provider == null) {
    throw new IllegalArgumentException("No such provider: " + providerName);
  }
  return withProvider(provider);
}

public KeyStoreBuilder withProvider ( final String providerName ) { Provider provider = Security . getProvider ( providerName ) ; if ( provider == null ) { throw new IllegalArgumentException ( "No such provider: " + providerName ) ; } return withProvider ( provider ) ; }
specifies the security provider to use for the keystore .
