code: def test_cache():
      assert Bint[1] is Bint[1]
      assert Real is Reals[()]
      assert Reals[2, 3] is Reals[2, 3]
  
imports: import io
  import pickle
  import pytest
  from funsor.domains import Bint, Real, Reals
label_desc: Use image node_id 3 for calling a global function with example usage: test_cache() without return types