class_docstr: Index subsetting transformer.
  
  In transform, subsets `X` to the indices in `y.index`.
  If `y` is None, returns `X` without subsetting.
  numpy-based `X` are interpreted as having a RangeIndex starting at n,
  where n is the number of numpy rows seen so far through `fit` and `update`.
  Non-pandas types are interpreted as having index as after conversion to pandas,
  via `datatypes.convert_to`, to the `"pd.DataFrame"` sktime type.
  
  Parameters
  ----------
  index_treatment : str, optional, one of "keep" (default) or "remove"
      determines which indices are kept in `Xt = transform(X, y)`
      "keep" = all indices in y also appear in Xt. If not present in X, NA is filled.
      "remove" = only indices that appear in both X and y are present in Xt.
  
  Examples
  --------
  >>> from sktime.transformations.series.subset import IndexSubset
  >>> from sktime.datasets import load_airline
  >>> X = load_airline()[0:32]
  >>> y = load_airline()[24:42]
  >>> transformer = IndexSubset()
  >>> X_subset = transformer.fit_transform(X=X, y=y)
docstr: Return testing parameter settings for the estimator.
  
  Parameters
  ----------
  parameter_set : str, default="default"
      Name of the set of test parameters to return, for use in tests. If no
      special parameters are defined for a value, will return `"default"` set.
      There are currently no reserved values for transformers.
  
  Returns
  -------
  params : dict or list of dict, default = {}
      Parameters to create testing instances of the class
      Each dict are parameters to construct an "interesting" test instance, i.e.,
      `MyClass(**params)` or `MyClass(**params[i])` creates a valid test instance.
      `create_test_instance` uses the first (or only) dictionary in `params`
code: def get_test_params(cls, parameter_set="default"):
      """Return testing parameter settings for the estimator.
  
      Parameters
      ----------
      parameter_set : str, default="default"
          Name of the set of test parameters to return, for use in tests. If no
          special parameters are defined for a value, will return `"default"` set.
          There are currently no reserved values for transformers.
  
      Returns
      -------
      params : dict or list of dict, default = {}
          Parameters to create testing instances of the class
          Each dict are parameters to construct an "interesting" test instance, i.e.,
          `MyClass(**params)` or `MyClass(**params[i])` creates a valid test instance.
          `create_test_instance` uses the first (or only) dictionary in `params`
      """
      params1 = {"index_treatment": "remove"}
      params2 = {"index_treatment": "keep"}
  
      return [params1, params2]
  
file_path: sktime/sktime/transformations/series/subset.py
imports: import pandas
  from sktime.transformations.base import BaseTransformer
label_desc: Use image node_id 3 for calling the IndexSubset obj's underlying member method code with example usage: obj.get_test_params(cls, parameter_set) and returns: list