code: def min_outputs(self):
      return 1
  
imports: import sys
  import pytest
  import numpy
  import nnabla
  import nnabla.functions
  import nnabla.parametric_functions
  import nnabla.initializer
  from nnabla.ext_utils import get_extension_context
  from nbla_test_utils import list_context
  from nnabla.testing import assert_allclose
  from nnabla.function import PythonFunction
  from nnabla.backward_functions import registry, register
label_desc: Use image node_id 2 for calling the IdentityForwardOnlyFunction obj's underlying member method code with example usage: obj.min_outputs() and returns: int