public String toString() {
        ToStringBuilder sb = new ToStringBuilder(this, ToStringStyle.DEFAULT_STYLE)
                .append("username", this.username)
                .append("enabled", this.enabled)
                .append("accountExpired", this.accountExpired)
                .append("credentialsExpired", this.credentialsExpired)
                .append("accountLocked", this.accountLocked);

        if (roles != null) {
            sb.append("Granted Authorities: ");

            int i = 0;
            for (Role role : roles) {
                if (i > 0) {
                    sb.append(", ");
                }
                sb.append(role.toString());
                i++;
            }
        } else {
            sb.append("No Granted Authorities");
        }
        return sb.toString();
    }