Lots of code here to construct a debug message that may not be shown in many cases (with a clone in the middle). Could this be simplified to
```
logger.debug("clearing list %s with options: %s", containerName, options)
```
See [Logger#debug(msg, args)](http://javadocs.jclouds.cloudbees.net/org/jclouds/logging/Logger.html#debug(java.lang.String, java.lang.Object...))