Fix Client to remove unchecked casting error. Fixes #6

This fixes the unchecked warning. `mvn clean install` output

```
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 10.793s
[INFO] Finished at: Wed Oct 02 10:58:50 PDT 2013
[INFO] Final Memory: 26M/198M
[INFO] ------------------------------------------------------------------------
```