code: def format_position(variant):
      """Gets a string representation of the variant's position.
  
      Args:
        variant: nucleus.genomics.v1.Variant.
  
      Returns:
        A string chr:start + 1 (as start is zero-based).
      """
      return "{}:{}".format(variant.reference_name, 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 8 for calling a global function with example usage: format_position(variant) and returns: str