code: def test_docstring_example_1():
      def model_1():
          a = pyro.sample("a", dist.Normal(0, 1))
          pyro.sample("b", dist.Normal(a, 1), obs=torch.tensor(0.0))
  
      actual = get_dependencies(model_1)
      expected = {
          "prior_dependencies": {
              "a": {"a": set()},
              "b": {"a": set(), "b": set()},
          },
          "posterior_dependencies": {
              "a": {"a": set(), "b": set()},
          },
      }
      assert actual == expected
  
imports: import pytest
  import torch
  import pyro
  import pyro.distributions
  from pyro.distributions.testing.fakes import NonreparameterizedNormal
  from pyro.infer.inspect import _deep_merge, get_dependencies, get_model_relations
label_desc: Use image node_id 2 for calling a global function with example usage: test_docstring_example_1() without return types