code: public Payload setAuthorizedParty(String authorizedParty) {
          this.authorizedParty = authorizedParty;
          this.put(PayloadConstants.AUTHORIZED_PARTY, authorizedParty);
          return this;
      }
docs: Sets the authorized party 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>