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: Compute the indicator mask.'
  
  Note that X must be the original data as passed to the imputer before
  any imputation, since imputation may be done inplace in some cases.
docstr_tok: ["Compute","the","indicator","mask",".","'","Note","that","X","must","be","the","original","data","as","passed","to","the","imputer","before","any","imputation",",","since","imputation","may","be","done","inplace","in","some","cases","."]
code: def _transform_indicator(self, X):
      """Compute the indicator mask.'
  
      Note that X must be the original data as passed to the imputer before
      any imputation, since imputation may be done inplace in some cases.
      """
      if self.add_indicator:
          if not hasattr(self, "indicator_"):
              raise ValueError(
                  "Make sure to call _fit_indicator before "
                  "_transform_indicator"
              )
          return self.indicator_.transform(X)
  
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 3 for calling the _BaseImputer obj's underlying member method code with example usage: obj._transform_indicator(X) and returns: self