@Override
    public String value() {
        return token;
    }
The <code>b64token</code> value as defined in
<a href="https://tools.ietf.org/html/rfc6750#section-2.1">RFC 6750 Section
2.1</a>

@return <code>b64token</code> value as defined in
        <a href="https://tools.ietf.org/html/rfc6750#section-2.1">RFC 6750
        Section 2.1</a>
clients/src/main/java/org/apache/kafka/common/security/oauthbearer/internals/secured/BasicOAuthBearerToken.java