code: def test_atan_fallback_expr():
      expr = ast.AtanExpr(ast.NumVal(2.0))
  
      interpreter = PythonInterpreter()
      interpreter.atan_function_name = NotImplemented
  
      expected_code = """
   def score(input):
      var1 = 2.0
      var2 = abs(var1)
      if var2 > 2.414213562373095:
          var0 = 1.0 / var2
      else:
          if var2 > 0.66:
              var0 = (var2 - 1.0) / (var2 + 1.0)
          else:
              var0 = var2
      var3 = var0
      var4 = var3 * var3
      if var2 > 2.414213562373095:
          var5 = -1.0
      else:
          var5 = 1.0
      if var2 <= 0.66:
          var6 = 0.0
      else:
          if var2 > 2.414213562373095:
              var6 = 1.5707963267948968
          else:
              var6 = 0.7853981633974484
      if var1 < 0.0:
          var7 = -1.0
      else:
          var7 = 1.0
      return ((var3 * var4 * (var4 * (var4 * (var4 * (var4 * -0.8750608600031904 - 16.157537187333652) - 75.00855792314705) - 122.88666844901361) - 64.85021904942025) / (194.5506571482614 + var4 * (485.3903996359137 + var4 * (432.88106049129027 + var4 * (165.02700983169885 + var4 * (24.858464901423062 + var4))))) + var3) * var5 + var6) * var7
  """  # noqa: E501
  
      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 7 for calling a global function with example usage: test_atan_fallback_expr() without return types