code: def get_lmdb_sample_info(self, txn, index):
      label_key = "label-%09d".encode() % index
      label = txn.get(label_key)
      if label is None:
          return None
      label = label.decode("utf-8")
      img_key = "image-%09d".encode() % index
      imgbuf = txn.get(img_key)
      return imgbuf, label
  
imports: import numpy
  import os
  from paddle.io import Dataset
  import lmdb
  import cv2
  import string
  import six
  import pickle
  from PIL import Image
  from .imaug import transform, create_operators
label_desc: Use image node_id 6 for calling the LMDBDataSet obj's underlying member method code with example usage: obj.get_lmdb_sample_info(txn, index) and returns: imgbuf,  label, None