code: def _fit_frame(self, X):
      if self.strategy == "mean":
          avg = X.mean(axis=0).values
      elif self.strategy == "median":
          avg = X.quantile().values
      elif self.strategy == "constant":
          avg = np.full(len(X.columns), self.fill_value)
      else:
          avg = [
              X[col].value_counts().nlargest(1).index
              for col in X.columns
          ]
          avg = np.concatenate(*dask.compute(avg))
  
      self.statistics_ = pd.Series(
          dask.compute(avg)[0], index=X.columns
      )
  
file_path: dask-ml/dask_ml/impute.py
imports: import dask
  import dask.array
  import dask.dataframe
  import numpy
  import pandas
  import sklearn.impute
  from .utils import check_array
label_desc: Use image node_id 4 for calling the SimpleImputer obj's underlying member method code with example usage: obj._fit_frame(X) without return types