code: private void writeMap(SerIterator itemIterator) throws IOException {
          // if key type is known and convertible use short key format, else use full bean format
          if (settings.getConverter().isConvertible(itemIterator.keyType())) {
              writeMapSimple(itemIterator);
          } else {
              writeMapComplex(itemIterator);
          }
      }
docs: write map