question: public X509CertPathImpl ( List < ? extends java . security . cert . Certificate > certs ) throws CertificateException { super ( "X.509" ) ; final int size = certs . size ( ) ; certificates = new ArrayList < X509Certificate > ( size ) ; for ( int i = 0 ; i < size ; i ++ ) { final java . security . cert . Certificate cert = certs . get ( i ) ; if ( ! ( cert instanceof X509Certificate ) ) { throw new CertificateException ( "Certificate " + i + " is not an X.509 certificate" ) ; } certificates . add ( ( X509Certificate ) cert ) ; } }
target:  Creates an instance of X.509 CertPath over the specified list of certificates.