code: def _scan_fill(self, method: str, limit: int) -> DataFrameOrSeries:
      # TODO: can this be more efficient?
  
      # first, compute the outer join between `self.obj` and the `bin_labels`
      # to get the sampling "gaps":
      upsampled = self.obj._align_to_index(
          self.grouping.bin_labels,
          how="outer",
          sort=True,
          allow_non_unique=True,
      )
  
      # fill the gaps:
      filled = upsampled.fillna(method=method)
  
      # filter the result to only include the values corresponding
      # to the bin labels:
      return filled._align_to_index(
          self.grouping.bin_labels,
          how="right",
          sort=False,
          allow_non_unique=True,
      )
  
imports: import pickle
  import numpy
  import pandas
  import cudf
  import cudf._lib.labeling
  import cudf.core.index
  from cudf._typing import DataFrameOrSeries
  from cudf.core.groupby.groupby import DataFrameGroupBy, GroupBy, SeriesGroupBy, _Grouping
  from cudf.core.tools.datetimes import _offset_alias_to_code, _unit_dtype_map
label_desc: Use image node_id 4 for calling the _Resampler obj's underlying member method code with example usage: obj._scan_fill(method, limit) and returns: filled