code: def variant_position(variant):
      """Returns a new Range at the start position of variant.
  
      Args:
        variant: nucleus.genomics.v1.Variant.
  
      Returns:
        A new Range with the same reference_name as variant and start but an end
        that is start + 1. This produces a range that is the single basepair of the
        start of variant, hence the name position.
      """
      return ranges.make_range(
          variant.reference_name, variant.start, variant.start + 1
      )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import collections
  import enum
  import itertools
  import six
  from third_party.nucleus.protos import variants_pb2
  from third_party.nucleus.util import ranges
  from third_party.nucleus.util import variantcall_utils
  from third_party.nucleus.util import vcf_constants
label_desc: Use image node_id 3 for calling a global function with example usage: variant_position(variant) and returns: ranges