class_docstr: Base class for all imputers.
  
  It adds automatically support for `add_indicator`.
class_docstr_tok: ["Base","class","for","all","imputers",".","It","adds","automatically","support","for","`","add_indicator","`","."]
docstr: Fit a MissingIndicator.
docstr_tok: ["Fit","a","MissingIndicator","."]
code: def _fit_indicator(self, X):
      """Fit a MissingIndicator."""
      if self.add_indicator:
          with cuml.using_output_type("cupy"):
              self.indicator_ = MissingIndicator(
                  missing_values=self.missing_values, error_on_new=False
              )
              self.indicator_.fit(X)
      else:
          self.indicator_ = None
  
imports: from ....internals import _deprecate_pos_args
  from ....common.array_descriptor import CumlArrayDescriptor
  from ....internals.array_sparse import SparseCumlArray
  from ..utils.validation import FLOAT_DTYPES
  from ..utils.validation import check_is_fitted
  from cuml.internals.mixins import AllowNaNTagMixin, SparseInputTagMixin, StringInputTagMixin
  from ..utils.skl_dependencies import BaseEstimator, TransformerMixin
  from ....thirdparty_adapters import _get_mask, _masked_column_median, _masked_column_mean, _masked_column_mode
  from cuml.internals.safe_imports import gpu_only_import_from
  import cuml
  from cuml.internals.safe_imports import gpu_only_import
  import numbers
  import warnings
  from cuml.internals.safe_imports import cpu_only_import
label_desc: Use image node_id 2 for calling the _BaseImputer obj's underlying member method code with example usage: obj._fit_indicator(X) without return types