code: def test_sigmoid_expr():
      expr = ast.SigmoidExpr(ast.NumVal(2.0))
  
      expected_code = """
  function Score([double[]] $InputVector) {
      return Sigmoid $(2.0)
  }
  function Sigmoid([double] $x) {
      if ($x -lt 0.0) {
          [double] $z = [math]::Exp($x)
          return $z / (1.0 + $z)
      }
      return 1.0 / (1.0 + [math]::Exp(-$x))
  }
  """
  
      interpreter = PowershellInterpreter()
      assert_code_equal(interpreter.interpret(expr), expected_code)
  
imports: from itertools import product
  import pytest
  from m2cgen import ast
  from m2cgen.interpreters import PowershellInterpreter
  from tests.utils import assert_code_equal
label_desc: Use image node_id 19 for calling a global function with example usage: test_sigmoid_expr() without return types