* @return <code>null</code>, if no conflict exists, else the first found
* file, which would be placed at the same location with the same
* name.
*/
private AbstractFile getConflict(AbstractFile file) {
AbstractFile result = null;
if (file instanceof FileDescriptor) {
FileDescriptor fd = (FileDescriptor) file;
if (fd.getTargetDirectory() != null) {
// DirectoryDescriptor returns them sorted.
AbstractFile[] children = fd.getTargetDirectory()