code: def __init__(
      self, file_name, sep, has_header, group_feature_num=None
  ):
      super(_SimpleStreamingFileReader, self).__init__(
          sep, group_feature_num
      )
      self._has_header = has_header
      self._file_name = file_name
  
file_path: catboost/catboost/python-package/catboost/eval/_readers.py
imports: import pandas
  from .utils import series_to_line
label_desc: Use image node_id 1 to create a new _SimpleStreamingFileReader object from inherited base classes: _BaseReader with example: obj = _SimpleStreamingFileReader(file_name, sep, has_header, group_feature_num)