* @param providerName the name of the index provider; may not be null
* @return the custom IndexFeedback instance; never null
*/
protected IndexFeedback forProvider( final String providerName ) {
assert providerName != null;
return new IndexFeedback() {
@Override
public void scan( String workspaceName,
IndexingCallback callback ) {
add(providerName, workspaceName, Path.ROOT_PATH, callback);