code: def _to_dataset_histograms(
      histogram_list, backend: pipeline_backend.PipelineBackend
  ):
      """Combines histogram_list to hist.DatasetHistograms."""
      histograms = backend.flatten(
          histogram_list, "Histograms to one collection"
      )
      # histograms: 5 elements collection with elements ContributionHistogram
  
      histograms = backend.to_list(histograms, "Histograms to List")
      # 1 element collection: [ContributionHistogram]
      return backend.map(
          histograms,
          _list_to_contribution_histograms,
          "To ContributionHistograms",
      )
  
imports: import bisect
  import operator
  from typing import List, Tuple
  import numpy
  import pipeline_dp
  from pipeline_dp import pipeline_backend, pipeline_functions
  from pipeline_dp.dataset_histograms import histograms
label_desc: Use image node_id 9 for calling a global function with example usage: _to_dataset_histograms(histogram_list, backend) and returns: backend