code: def __init__(self, num_of_data=1000, shuffle=False):
      self._num_of_data = num_of_data
      self._data = list(range(num_of_data))
      if shuffle:
          random.shuffle(self._data)
      self.shuffle = shuffle
      self._index = 0
      self.need_reinitialize = False
  
file_path: fastNLP/tests/helpers/datasets/normal_data.py
imports: import numpy
  import random
label_desc: Use image node_id 1 to create a new NormalSampler object  with example: obj = NormalSampler(num_of_data, shuffle)