code: def test_unary_exp():
      z = Tensor(randn(2))["z"]
      c = Constant(OrderedDict(x=Bint[3], y=Real), z)
  
      result = c.exp()
      assert result.const_inputs == c.const_inputs
      assert_close(result.arg, c.arg.exp())
  
file_path: funsor/test/test_constant.py
imports: from collections import OrderedDict
  import funsor.ops
  from funsor.constant import Constant
  from funsor.delta import Delta
  from funsor.domains import Bint, Real
  from funsor.tensor import Tensor
  from funsor.terms import Number, Variable, to_data, to_funsor
  from funsor.testing import assert_close, randn, requires_backend
label_desc: Use image node_id 3 for calling a global function with example usage: test_unary_exp() without return types