How to use the pyocr.builders.LineBox function in pyocr

def clone_page_content(src_page, dst_page, mapping, salt):
    src_boxes_lines = src_page.boxes
    dst_boxes_lines = []
    for src_boxes_line in src_boxes_lines:
        src_boxes = src_boxes_line.word_boxes
        dst_boxes_line = [clone_box(box, mapping, salt) for box in src_boxes]
        dst_boxes_line = LineBox(dst_boxes_line, src_boxes_line.position)
        dst_boxes_lines.append(dst_boxes_line)
    dst_page.boxes = dst_boxes_lines
    dst_page.img = clone_img(src_page.img)

def clone_page_content(src_page, dst_page, mapping, salt):
    src_boxes_lines = src_page.boxes
    dst_boxes_lines = []
    for src_boxes_line in src_boxes_lines:
        src_boxes = src_boxes_line.word_boxes
        dst_boxes_line = [clone_box(box, mapping, salt) for box in src_boxes]
        dst_boxes_line = LineBox(dst_boxes_line, src_boxes_line.position)
        dst_boxes_lines.append(dst_boxes_line)
    dst_page.boxes = dst_boxes_lines
    dst_page.img = clone_img(src_page.img)

try:
            box_builder = pyocr.builders.LineBoxBuilder()
            with self.fs.open(boxfile, 'r') as file_desc:
                boxes = box_builder.read_file(file_desc)
            if boxes != []:
                return boxes
            # fallback: old format: word boxes
            # shouldn't be used anymore ...
            box_builder = pyocr.builders.WordBoxBuilder()
            with self.fs.open(boxfile, 'r') as file_desc:
                boxes = box_builder.read_file(file_desc)
            if len(boxes) <= 0:
                return []
            logger.warning("WARNING: Doc %s uses old box format" %
                           (str(self.doc)))
            return [pyocr.builders.LineBox(boxes, boxes[0].position)]
        except IOError as exc:
            logger.error("Unable to get boxes for '%s': %s"
                         % (self.doc.docid, exc))
            return []