class_docstr: Class for managing the user data in nebullvm.
  
  Attributes:
      data_reader(Sequence): Object implementing the __getitem__, the
          __len__ and the __iter__/__next__ APIs. It should read the
          user data and return tuples of tensors for feeding the models.
code: def __next__(self):
      if self._pointer < len(self):
          data = self[self._pointer]
          self._pointer += 1
          return data
      else:
          raise StopIteration
  
imports: from typing import Sequence, List, Tuple, Any, Union, Iterable
  import numpy
  from loguru import logger
  from nebullvm.config import MIN_DIM_INPUT_DATA
  from nebullvm.optional_modules.tensorflow import tensorflow
  from nebullvm.optional_modules.torch import torch, Dataset, DataLoader
  from nebullvm.tools.onnx import convert_to_numpy
label_desc: Use image node_id 5 for calling the DataManager obj's underlying member method code with example usage: obj.__next__() and returns: data