DOMInputCapsule.readIntSavableMap does not check exceptions

The code is as follows:

public IntMap<? extends Savable> readIntSavableMap(String name, IntMap<? extends Savable> defVal) throws IOException {
...

                                if (n instanceof Element && n.getNodeName().equals("MapEntry")) {
                                        Element elem = (Element) n;
                                        currentElem = elem;
                                        int key = Integer.parseInt(currentElem.getAttribute("key"));
                                        Savable val = readSavable("Savable", null);
                                        ret.put(key, val);
                                }                  
         ...
    }

Here Integer.parseInt(currentElem.getAttribute("key")) can throw NumberFormatException. The other methods of this class catch and rethrow IOException. An example is as follows:

public byte[] readByteArray(String name, byte[] defVal) throws IOException {
  try {...
      for (int i = 0; i < strings.length; i++) {
              tmp[i] = Byte.parseByte(strings[i]);
       }...
  }catch (IOException ioe) {
            throw ioe;
        } catch (NumberFormatException nfe) {

            IOException io = new IOException(nfe.toString());
            io.initCause(nfe);
            throw io;

        } catch (DOMException de) {
            IOException io = new IOException(de.toString());
            io.initCause(de);
            throw io;
        }
    }

Start at DOMInputCapsule.readIntSavableMap and compare its exception handling with the readByteArray example in the issue. Check how malformed MapEntry key values are reported, then verify that NumberFormatException is exposed as an IOException with the original cause while preserving existing IOException behavior.