public String getMeta(String key)
    {
        return metadata.get(key);
    }
@Test
    public void testGetMeta()
    {
        ZCert cert = new ZCert();

        cert.setMeta("version", "1");
        ZMetadata meta = cert.getMetadata();
        String version = meta.get("version");
        assertThat(version, is("1"));

        meta.set("version", "2");
        version = cert.getMeta("version");
        assertThat(version, is("2"));
    }