_files = existingFiles;
List fileNamesInContainer = WGUtils.toLowerCase(con.getFileNames());
fileNamesInContainer.removeAll(existingFiles.keySet());
Iterator deletedFiles = fileNamesInContainer.iterator();
while (deletedFiles.hasNext()) {
con.removeFile((String) deletedFiles.next());
con.save();
}
// Update metadata and save
FCMetadata metaData = (FCMetadata) readMetaData();