code: def test_simple_rust_code():
      name_expr = ("test", (x + y) * z)
      (result,) = codegen(name_expr, "Rust", header=False, empty=False)
      assert result[0] == "test.rs"
      source = result[1]
      expected = (
          "fn test(x: f64, y: f64, z: f64) -> f64 {\n"
          "    let out1 = z*(x + y);\n"
          "    out1\n"
          "}\n"
      )
      assert source == expected
  
imports: from io import StringIO
  from sympy.core import S, symbols, pi, Catalan, EulerGamma, Function
  from sympy.core.relational import Equality
  from sympy.functions.elementary.piecewise import Piecewise
  from sympy.utilities.codegen import RustCodeGen, codegen, make_routine
  from sympy.testing.pytest import XFAIL
  import sympy
label_desc: Use image node_id 2 for calling a global function with example usage: test_simple_rust_code() without return types