code: def overlap_len(range1, range2):
      """Computes the number of overlapping bases of range1 and range2.
  
      Args:
        range1: nucleus.genomics.v1.Range.
        range2: nucleus.genomics.v1.Range.
  
      Returns:
        int. The number of basepairs in common. 0 if the ranges are not on the same
        contig.
      """
      if range1.reference_name != range2.reference_name:
          return 0
      return max(
          0,
          (
              min(range1.end, range2.end)
              - max(range1.start, range2.start)
          ),
      )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import collections
  import re
  from typing import Dict, Iterable, Optional, Sequence
  from absl import logging
  from etils import epath
  import intervaltree
  import six
  from third_party.nucleus.io import bed
  from third_party.nucleus.protos import position_pb2
  from third_party.nucleus.protos import range_pb2
  from third_party.nucleus.protos import reference_pb2
  from third_party.nucleus.protos import variants_pb2
label_desc: Use image node_id 16 for calling a global function with example usage: overlap_len(range1, range2) and returns: max, int