old_contents: """
  The :mod:`hcibench.pipeline` module provides a flexible infrastructure for
  data processing and implements some common types of processing blocks.
  """
  
  from .base import PipelineBlock, Pipeline, PassthroughPipeline
  from .common import Windower, Filter, FeatureExtractor
  
  __all__ = ['PipelineBlock',
             'Pipeline',
             'PassthroughPipeline',
             'Windower',
             'Filter',
             'FeatureExtractor',
             'Estimator']
  
new_contents: """
  The :mod:`hcibench.pipeline` module provides a flexible infrastructure for
  data processing and implements some common types of processing blocks.
  """
  
  from .base import PipelineBlock, Pipeline, PassthroughPipeline
  from .common import Windower, Filter, FeatureExtractor, Estimator
  
  __all__ = ['PipelineBlock',
             'Pipeline',
             'PassthroughPipeline',
             'Windower',
             'Filter',
             'FeatureExtractor',
             'Estimator']
  
subject: Make Estimator importable from pipeline.