presto-spi/src/main/java/io/prestosql/spi/security/Identity.java/Identity/from
class Identity:    public static Builder from(Identity identity)
    {
        return new Builder(identity.getUser())
                .withPrincipal(identity.getPrincipal())
                .withRoles(identity.getRoles())
                .withExtraCredentials(identity.getExtraCredentials());
    }