public void updateContent(Properties prop) {
        {
            String value = prop.getProperty(ACCESS_KEY);
            if (value != null) {
                this.accessKey = value.trim();
            }
        }
        {
            String value = prop.getProperty(SECRET_KEY);
            if (value != null) {
                this.secretKey = value.trim();
            }
        }
        {
            String value = prop.getProperty(SECURITY_TOKEN);
            if (value != null) {
                this.securityToken = value.trim();
            }
        }
    }
@Test
    public void updateContentTest() {
        SessionCredentials sessionCredentials = new SessionCredentials();
        Properties properties = new Properties();
        properties.setProperty(SessionCredentials.ACCESS_KEY,"RocketMQ");
        properties.setProperty(SessionCredentials.SECRET_KEY,"12345678");
        properties.setProperty(SessionCredentials.SECURITY_TOKEN,"abcd");
        sessionCredentials.updateContent(properties);
    }