code: def combine_variant_datasets(
      vdss: List[VariantDataset],
  ) -> VariantDataset:
      reference = combine_references(
          [vds.reference_data for vds in vdss]
      )
      no_variant_key = [
          vds.variant_data.key_rows_by("locus") for vds in vdss
      ]
  
      variants = combine_gvcfs(no_variant_key)
      return VariantDataset(
          reference,
          variants._key_rows_by_assert_sorted("locus", "alleles"),
      )
  
imports: import math
  from typing import Collection, Optional, Set, Union, List, Tuple, Dict
  import hail
  from hail import MatrixTable, Table
  from hail.experimental.function import Function
  from hail.expr import StructExpression, unify_all, construct_expr
  from hail.expr.expressions import expr_bool, expr_str
  from hail.genetics.reference_genome import reference_genome_type
  from hail.ir import Apply, TableMapRows
  from hail.typecheck import oneof, sequenceof, typecheck
  from ..variant_dataset import VariantDataset
label_desc: Use image node_id 10 for calling a global function with example usage: combine_variant_datasets(vdss) and returns: VariantDataset