public String extractOpenid(String body) {
        var openid = extractParameter(body, OPENID_REGEX, true);
        return openid;
    }
<p>extractOpenid.</p>

@param body a {@link String} object
@return a {@link String} object
pac4j-oauth/src/main/java/org/pac4j/oauth/profile/qq/QQProfileDefinition.java