code: def test_sigmoid_expr():
      expr = ast.SigmoidExpr(ast.NumVal(2.0))
  
      expected_code = """
  def score(input)
      sigmoid(2.0)
  end
  def sigmoid(x)
      if x < 0.0
          z = Math.exp(x)
          return z / (1.0 + z)
      end
      1.0 / (1.0 + Math.exp(-x))
  end
  """
  
      interpreter = RubyInterpreter()
      assert_code_equal(interpreter.interpret(expr), expected_code)
  
imports: from itertools import product
  import pytest
  from m2cgen import ast
  from m2cgen.interpreters import RubyInterpreter
  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