class_docstr: BaseDataset for PGLBox.
      
code: def __init__(
      self,
      chunk_num,
      config,
      holder_list,
      embedding=None,
      dist_graph=None,
      is_predict=False,
  ):
      self.ins_ready_sem = threading.Semaphore(0)
      self.could_load_sem = threading.Semaphore(2)
      self.dist_graph = dist_graph
      self.config = config
      self.embedding = embedding
      self.chunk_num = chunk_num
      self.holder_list = holder_list
      self.is_predict = is_predict
  
imports: import os
  import time
  import threading
  import traceback
  import numpy
  import paddle
  from paddle.distributed import fleet
  import paddle.fluid
  from pgl.utils.logger import log
  import util
  import helper
  from place import get_cuda_places
  import models.model_util
label_desc: Use image node_id 1 to create a new BaseDataset object from inherited base classes: object with example: obj = BaseDataset(chunk_num, config, holder_list, embedding, dist_graph, is_predict)