class_docstr: A dataset wrapping over a RecordIO (.rec) file.
  
  Each sample is a string representing the raw content of an record.
  
  Parameters
  ----------
  filename : str
      Path to rec file.
code: def __mx_handle__(self):
      from ._internal import RecordFileDataset as _RecordFileDataset
  
      return _RecordFileDataset(
          rec_file=self.filename, idx_file=self.idx_file
      )
  
imports: import os
  from ...None import recordio, ndarray
  from ...util import default_array
label_desc: Use image node_id 4 for calling the RecordFileDataset obj's underlying member method code with example usage: obj.__mx_handle__() and returns: _RecordFileDataset