code: def _nonref_genotype_count(variant):
      """Returns the number of non-reference alleles in the called genotype."""
      return sum(
          g > 0 for g in variant_utils.only_call(variant).genotype
      )
  
imports: import copy
  import itertools
  from absl import flags
  from absl import logging
  import numpy
  from third_party.nucleus.util import genomics_math
  from third_party.nucleus.util import variant_utils
label_desc: Use image node_id 7 for calling a global function with example usage: _nonref_genotype_count(variant) and returns: sum