docstr: Raises `ValueError` if `self._parallel_params` specifies a `key` in
  `self._fixed_params` that should be distributed, but
  `len(self._fixed_params[key])` does not equal `n_timeseries`.
docstr_tok: ["Raises","`","ValueError","`","if","`","self._parallel_params","`","specifies","a","`","key","`","in","`","self._fixed_params","`","that","should","be","distributed",",","but","`","len","(","self._fixed_params","[","key","]",")","`","does","not","equal","`","n_timeseries","`","."]
code: def _check_fixed_params(self, n_timeseries: int) -> None:
      """
      Raises `ValueError` if `self._parallel_params` specifies a `key` in
      `self._fixed_params` that should be distributed, but
      `len(self._fixed_params[key])` does not equal `n_timeseries`.
      """
      for key in self._parallel_params:
          raise_if(
              n_timeseries > len(self._fixed_params[key]),
              f"{n_timeseries} TimeSeries were provided "
              f"but only {len(self._fixed_params[key])} {key} values "
              f"were specified upon initialising {self.name}.",
          )
      return None
  
imports: from abc import ABC, abstractmethod
  from typing import Any, Generator, List, Mapping, Optional, Sequence, Union
  import numpy
  import xarray
  from darts import TimeSeries
  from darts.logging import get_logger, raise_if, raise_if_not
  from darts.utils import _build_tqdm_iterator, _parallel_apply
label_desc: Use image node_id 7 for calling the BaseDataTransformer obj's underlying member method code with example usage: obj._check_fixed_params(n_timeseries) and returns: None