class_docstr: A simple Datasets containing a list of paths given the file_pattern.
  
  Parameters
  ----------
  file_pattern: str
      Path to the input text files.
code: def __init__(self, file_pattern):
      if not isinstance(file_pattern, str):
          raise TypeError(
              "file_pattern must be str, but got %s"
              % type(file_pattern)
          )
      files = []
      for pattern in file_pattern.split(","):
          files.extend(glob.glob(os.path.expanduser(pattern.strip())))
      files = sorted(files)
      if len(files) == 0:
          raise ValueError(
              'Cannot find any file with path "%s"' % file_pattern
          )
      super().__init__(files)
  
imports: import io
  import os
  import gc
  import glob
  import pickle
  import warnings
  import multiprocessing
  from functools import partial
  import numpy
  from mxnet import context, npx
  from mxnet.gluon.data import ArrayDataset, SimpleDataset
  from mxnet.gluon.data.dataloader import ForkingPickler, _as_in_context, default_mp_batchify_fn, default_batchify_fn
label_desc: Use image node_id 1 to create a new _PathDataset object from inherited base classes: SimpleDataset with example: obj = _PathDataset(file_pattern)