I need to parse xml into a HashMap where the 'key' is the concatenation of two elements attributes.
The xml looks like :

```
<map>
  <parent key='p1'><child key='c1'> value1</child></parent>
  <parent key='p2'><child key='c2'> value1</child></parent>
</map>

```

In the 1st entry of map, I want to put 'p1.c1'as the map key while 'value1' as the map value. How to achieve that?