code: def _read32(bytestream):
      dt = numpy.dtype(numpy.uint32).newbyteorder(">")
      return numpy.frombuffer(bytestream.read(4), dtype=dt)[0]
  
file_path: BigDL/python/dllib/src/bigdl/dllib/feature/dataset/mnist.py
imports: import gzip
  import numpy
  from bigdl.dllib.feature.dataset import base
  from bigdl.dllib.feature.dataset.transformer import *
  from bigdl.dllib.utils.log4Error import *
label_desc: Use image node_id 1 for calling a global function with example usage: _read32(bytestream) and returns: numpy