docs: def to_csv(self, filename, delimiter=",", recommended_only=False, include_io=True):
          """
          Return a CSV for each model and dataset.
  
          Parameters
          ----------
          filename : str or file
              Either the file name (string) or an open file (file-like object)
              where the data will be saved.
          delimiter : str, optional
              Delimiter used in CSV file between fields.
          recommended_only : bool, optional
              If True, only recommended models for each session are included. If
              no model is recommended, then a row with it's ID will be included,
              but all fields will be null.
          include_io :  bool, optional
              If True, then the input/output files from BMDS will also be
              included, specifically the (d) input file and the out file.
  
          Returns
          -------
          None
  
          """
          df = self.to_df(recommended_only, include_io)
          df.to_csv(filename, index=False, sep=delimiter)