@Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;

        SessionCredentials other = (SessionCredentials) obj;
        if (accessKey == null) {
            if (other.accessKey != null)
                return false;
        } else if (!accessKey.equals(other.accessKey))
            return false;

        if (secretKey == null) {
            if (other.secretKey != null)
                return false;
        } else if (!secretKey.equals(other.secretKey))
            return false;

        if (signature == null) {
            return other.signature == null;
        } else return signature.equals(other.signature);
    }
@Test
    public void equalsTest() {
        SessionCredentials sessionCredentials = new SessionCredentials("RocketMQ","12345678");
        sessionCredentials.setSecurityToken("abcd");
        SessionCredentials other = new SessionCredentials("RocketMQ","12345678","abcd");
        Assert.assertTrue(sessionCredentials.equals(other));
    }