code: def _compute_l1_contributions_histogram(
      col, backend: pipeline_backend.PipelineBackend
  ):
      """Computes histogram of the number of distinct records contributed by a privacy id.
  
      This histogram contains: number of privacy ids which contributes to 1
      record, to 2 records etc.
  
      Args:
          col: collection with elements (privacy_id, partition_key).
          backend: PipelineBackend to run operations on the collection.
      Returns:
          1 element collection, which contains the computed hist.Histogram.
      """
      col = backend.keys(col, "Drop partition id")
      # col: (pid)
  
      col = backend.count_per_element(
          col, "Compute records per privacy id"
      )
      # col: (pid, num_records)
  
      col = backend.values(col, "Drop privacy id")
      # col: (int)
  
      return _compute_frequency_histogram(
          col, backend, hist.HistogramType.L1_CONTRIBUTIONS
      )
  
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 11 for calling a global function with example usage: _compute_l1_contributions_histogram(col, backend) and returns: _compute_frequency_histogram