code: public boolean HasKeyID(String id) {
          CBORObject thatObj = (id == null) ? null : CBORObject.FromObject(id);
          CBORObject thisObj = get(KeyKeys.KeyId);
          boolean result;
          if (thatObj == null) {
              result = (thisObj == null);
          } else {
              result = thatObj.equals(thisObj);
          }    
          return result;
      }
docs: Compares the key's assigned identifier with the provided value, indicating if the values are
  the same.
  
  @param id
  the identifier to compare or {@code null} to check for no assignment.
  @return {@code true} if the current key has the provided identifier assigned, or {@code false}
  otherwise