code: private File getCacheDir() {
  		// Get the root cache dir
  		File cacheDir = new File(configuration.getOptimizerCacheDir());
  		if (!cacheDir.exists()) {
  			cacheDir.mkdir();
  		}
  
  		// Get the directory that represent the host directory
  		// return FootprintGenerator.footprint(getMandatory(P_ROX_URL));
  		File roxCacheDir = new File(cacheDir, configuration.getServerConfiguration().getBaseUrlFootprint());
  		if (!roxCacheDir.exists()) {
  			roxCacheDir.mkdirs();
  		}
  		
  		return roxCacheDir;
  	}
docs: Get the cache directory. if not exist, it is created and returned.
  
  @return The cache base directory