protected Map<String, String> getSecurityHeaders(String namespace, String group, String serviceName) {
        RequestResource resource = RequestResource.namingBuilder().setNamespace(namespace).setGroup(group)
                .setResource(serviceName).build();
        Map<String, String> result = this.securityProxy.getIdentityContext(resource);
        result.putAll(getAppHeaders());
        return result;
    }
@Test
    void testGetSecurityHeadersForRam() throws Exception {
        String ak = "aa";
        String sk = "bb";
        Map<String, String> mockIdentityContext = new HashMap<>();
        String serviceName = "aaa";
        mockIdentityContext.put("ak", ak);
        String data = System.currentTimeMillis() + "@@" + serviceName;
        mockIdentityContext.put("data", data);
        mockIdentityContext.put("signature", SignUtil.sign(data, sk));
        when(sc.getIdentityContext(any(RequestResource.class))).thenReturn(mockIdentityContext);
        AbstractNamingClientProxy proxy = new MockNamingClientProxy(sc);
        Map<String, String> spasHeaders = proxy.getSecurityHeaders("", "", serviceName);
        assertEquals(4, spasHeaders.size());
        assertEquals(AppNameUtils.getAppName(), spasHeaders.get("app"));
        assertEquals(ak, spasHeaders.get("ak"));
        assertTrue(spasHeaders.get("data").endsWith("@@" + serviceName));
        String expectSign = SignUtil.sign(spasHeaders.get("data"), sk);
        assertEquals(expectSign, spasHeaders.get("signature"));
        
    }