public String mintNewSecureToken() {
        byte[] tokenBuffer = new byte[15];
        secureTokenGenerator.nextBytes(tokenBuffer);
        return Base64.getUrlEncoder().encodeToString(tokenBuffer);
    }
@Test
    void testMintNewSecureToken() {
        String token = pushConnectionRegistry.mintNewSecureToken();

        assertNotNull(token);
        assertEquals(20, token.length()); // 15 bytes become 20 characters when Base64-encoded
    }