code: def test_get_context(self):
      tl1 = tlocus("GRCh37")
      tl2 = tlocus("GRCh38")
  
      types_and_rgs = [
          (
              [
                  tint32,
                  tint64,
                  tfloat32,
                  tfloat64,
                  tstr,
                  tbool,
                  tcall,
                  tinterval(tset(tint32)),
                  tdict(tstr, tarray(tint32)),
                  tndarray(tstr, 1),
                  tstruct(),
                  tstruct(x=tint32, y=tint64, z=tarray(tset(tstr))),
                  tunion(),
                  tunion(a=tint32, b=tstr),
                  ttuple(tstr, tint32),
                  ttuple(),
              ],
              set(),
          ),
          (
              [
                  tl1,
                  tinterval(tl1),
                  tdict(tstr, tl1),
                  tndarray(tl1, 2),
                  tinterval(tl1),
                  tset(tinterval(tl1)),
                  tstruct(a=tint32, b=tint32, c=tarray(tl1)),
                  tunion(a=tint32, b=tl1),
                  ttuple(tarray(tint32), tl1, tstr, tint32, tbool),
              ],
              {"GRCh37"},
          ),
          (
              [
                  tdict(tl1, tl2),
                  ttuple(tarray(tl2), tl1, tstr, tint32, tbool),
              ],
              {"GRCh37", "GRCh38"},
          ),
      ]
  
      for types, rgs in types_and_rgs:
          for t in types:
              self.assertEqual(t.get_context().references, rgs)
  
imports: from typing import Optional
  import unittest
  from hail.expr import coercer_from_dtype
  from hail.expr.types import *
  from hail.genetics import reference_genome
  from ..helpers import *
  from hail.utils.java import Env
label_desc: Use image node_id 10 for calling the Tests obj's underlying member method code with example usage: obj.test_get_context() without return types