code: def test_summarize_variants_ti_tv(self):
      mt = hl.import_vcf(resource("sample.vcf"))
      # check that summarize can run with the print control flow
      hl.summarize_variants(mt, handler=lambda s: ())
      r = hl.summarize_variants(mt, show=False)
      assert r["allele_types"] == {
          "Deletion": 27,
          "Insertion": 18,
          "SNP": 301,
      }
      assert r["contigs"] == {"20": 346}
      assert r["n_variants"] == 346
      assert r["r_ti_tv"] == 2.5
      assert r["allele_counts"] == {2: 346}
  
imports: import unittest
  import hail
  import hail.expr.aggregators
  from hail.utils.misc import new_temp_file
  from ..helpers import *
  from hail.methods.qc import VEPConfigGRCh37Version85, VEPConfigGRCh38Version95
label_desc: Use image node_id 16 for calling the Tests obj's underlying member method code with example usage: obj.test_summarize_variants_ti_tv() without return types