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