code: @Override
  	public <S extends T> Optional<S> findOne(final Example<S> example) {
  		final ArangoCursor cursor = findAllInternal((Pageable) null, example, new HashMap());
  		return cursor.hasNext() ? Optional.ofNullable((S) cursor.next()) : Optional.empty();
  	}
docs: Finds one document which matches the given example object
  
  @param example
  example object to construct query with
  @param <S>
  @return An object representing the example if it exists, else null