code: def test_stanc_invalid_assignment():
      program_code = "parameters {real z;} model {z = 3;}"
      with pytest.raises(ValueError, match=r"Semantic error"):
          stan.build(program_code=program_code)
  
imports: import pytest
  import stan
label_desc: Use image node_id 3 for calling a global function with example usage: test_stanc_invalid_assignment() without return types