code: def n_zeroes(l):
      """Returns the number of elements of l that are 0."""
      return sum(1 for x in l if x == 0)
  
imports: import collections
  import copy
  import enum
  import heapq
  import itertools
  from absl import logging
  from deepvariant.labeler import variant_labeler
  from deepvariant.protos import deepvariant_pb2
  from third_party.nucleus.io import fasta
  from third_party.nucleus.util import ranges
  from third_party.nucleus.util import variant_utils
  from third_party.nucleus.util import variantcall_utils
label_desc: Use image node_id 17 for calling a global function with example usage: n_zeroes(l) and returns: sum