code: def test_log1p_fallback_expr():
      expr = ast.Log1pExpr(ast.NumVal(2.0))
  
      interpreter = PythonInterpreter()
      interpreter.log1p_function_name = NotImplemented
  
      expected_code = """
  import math
  def score(input):
      var1 = 2.0
      var2 = 1.0 + var1
      var3 = var2 - 1.0
      if var3 == 0.0:
          var0 = var1
      else:
          var0 = var1 * math.log(var2) / var3
      return var0
  """
  
      assert_code_equal(interpreter.interpret(expr), expected_code)
  
file_path: m2cgen/tests/test_fallback_expressions.py
imports: import pytest
  from m2cgen import ast
  from m2cgen.interpreters import CInterpreter, PythonInterpreter
  from tests.utils import assert_code_equal
label_desc: Use image node_id 6 for calling a global function with example usage: test_log1p_fallback_expr() without return types