code: def iterable_len(iterable):
      """Returns the length of a Python iterable, by advancing it."""
      return sum(1 for _ in iterable)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  from absl import flags
  from absl.testing import absltest
  from etils import epath
  import six
  from third_party.nucleus.protos import position_pb2
  from third_party.nucleus.protos import reads_pb2
  from third_party.nucleus.protos import struct_pb2
  from third_party.nucleus.protos import variants_pb2
  from third_party.nucleus.util import cigar
label_desc: Use image node_id 9 for calling a global function with example usage: iterable_len(iterable) and returns: sum