public String validateString(String name) throws ValidateException {
        return validateString(name, true);
    }
Validates that the configured URL that:

<li>
    <ul>is well-formed</ul>
    <ul>contains a scheme</ul>
    <ul>uses either HTTP, HTTPS, or file protocols</ul>
</li>

No effort is made to connect to the URL in the validation step.
clients/src/main/java/org/apache/kafka/common/security/oauthbearer/internals/secured/ConfigurationUtils.java