code: def test_sigmoid_expr():
      expr = ast.SigmoidExpr(ast.NumVal(2.0))
  
      expected_code = r"""
  module Model where
  score :: [Double] -> Double
  score input =
      sigmoid (2.0)
  sigmoid :: Double -> Double
  sigmoid x
      | x < 0.0 = z / (1.0 + z)
      | otherwise = 1.0 / (1.0 + exp (-x))
    where
      z = exp x
  """
  
      interpreter = HaskellInterpreter()
      assert_code_equal(interpreter.interpret(expr), expected_code)
  
imports: from itertools import product
  import pytest
  from m2cgen import ast
  from m2cgen.interpreters import HaskellInterpreter
  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