class_docstr: Splitter needs providing some parameters to create folds and some "reader",
  that can read source.
class_docstr_tok: ["Splitter","needs","providing","some","parameters","to","create","folds","and","some","``","reader","''",",","that","can","read","source","."]
code: def create_fold(self, fold_set, name, id):
      file_name = self.create_name_from_id(name, id)
      fold_file = _FoldFile(
          fold_set,
          file_name,
          sep=self._line_reader.get_separator(),
          column_description=self._column_description,
      )
      self._folds_storage.add(fold_file)
      return fold_file
  
file_path: catboost/catboost/python-package/catboost/eval/_splitter.py
imports: import random
  from ._fold_storage import FoldStorage
  from ._fold_storage import _FoldFile
label_desc: Use image node_id 7 for calling the _Splitter obj's underlying member method code with example usage: obj.create_fold(fold_set, name, id) and returns: fold_file