public String principalClaimName() {
        return principalClaimName;
    }
Return the (always non-null/non-empty) principal claim name

@return the (always non-null/non-empty) principal claim name
clients/src/main/java/org/apache/kafka/common/security/oauthbearer/internals/unsecured/OAuthBearerUnsecuredJws.java