code: public JWSHeader setJwkUrl(String jwkUrl) {
          this.jwkUrl = jwkUrl;
          this.put(HeaderConstants.JWK_URL, jwkUrl);
          return this;
      }
docs: Sets the JSON Web Key URL header parameter that is an absolute URL that refers to a resource
  for a set of JSON-encoded public keys, one of which corresponds to the key that was used to
  digitally sign the JWS or {@code null} for none.
  
  <p>
  Overriding is only supported for the purpose of calling the super implementation and changing
  the return type, but nothing else.
  </p>