/**
  * List existent indices in a collection
  *
  * <p>{@sample.xml ../../../doc/mongo-connector.xml.sample mongo:list-indices}
  *
  * @param collection the name of the collection
  * @return a collection of {@link DBObject} with indices information
  */
 @Processor
 public Collection<DBObject> listIndices(String collection) {
   return client.listIndices(collection);
 }