presto-client/src/main/java/io/prestosql/client/SpnegoHandler.java/SpnegoHandler/doAs
class SpnegoHandler:    private static <T> T doAs(Subject subject, GssSupplier<T> action)
            throws GSSException
    {
        try {
            return Subject.doAs(subject, (PrivilegedExceptionAction<T>) action::get);
        }
        catch (PrivilegedActionException e) {
            Throwable t = e.getCause();
            throwIfInstanceOf(t, GSSException.class);
            throwIfUnchecked(t);
            throw new RuntimeException(t);
        }
    }