docs: def fit(self, X, y=None):
              """
              Compute the min, max and median for all columns in the DataFrame. For more information,
              please see the :func:`~tsfresh.utilities.dataframe_functions.get_range_values_per_column` function.
  
              :param X: DataFrame to calculate min, max and median values on
              :type X: pandas.DataFrame
              :param y: Unneeded.
              :type y: Any
  
              :return: the estimator with the computed min, max and median values
              :rtype: Imputer
              """
              if not isinstance(X, pd.DataFrame):
                  X = pd.DataFrame(X)
  
              col_to_max, col_to_min, col_to_median = get_range_values_per_column(X)
  
              if self.col_to_NINF_repl_preset is not None:
                  if not set(X.columns) >= set(self.col_to_NINF_repl_preset.keys()):
                      raise ValueError("Preset dictionary 'col_to_NINF_repl_preset' contain more keys "
                                       "than the column names in X")
                  col_to_min.update(self.col_to_NINF_repl_preset)
              self._col_to_NINF_repl = col_to_min
  
              if self.col_to_PINF_repl_preset is not None:
                  if not set(X.columns) >= set(self.col_to_PINF_repl_preset.keys()):
                      raise ValueError("Preset dictionary 'col_to_PINF_repl_preset' contain more keys "
                                       "than the column names in X")
                  col_to_max.update(self.col_to_PINF_repl_preset)
              self._col_to_PINF_repl = col_to_max
  
              if self.col_to_NAN_repl_preset is not None:
                  if not set(X.columns) >= set(self.col_to_NAN_repl_preset.keys()):
                      raise ValueError("Preset dictionary 'col_to_NAN_repl_preset' contain more keys "
                                       "than the column names in X")
                  col_to_median.update(self.col_to_NAN_repl_preset)
              self._col_to_NAN_repl = col_to_median
  
              return self