code: def _abs_difference(x, y):
      """a measure of the relative difference between two numbers."""
      return np.abs(x - y) / (1e-4 + (np.abs(x) + np.abs(y)) / 2)
  
imports: import os
  import pytest
  import requests
  from modelkit import ModelLibrary, testing
  from modelkit.core.models.tensorflow_model import AsyncTensorflowModel, TensorflowModel, has_tensorflow
  from modelkit.core.settings import LibrarySettings
  from modelkit.testing import tf_serving_fixture
  from modelkit.utils.tensorflow import write_config
  from tests import TEST_DIR
  from tests.conftest import skip_unless
label_desc: Use image node_id 9 for calling a global function with example usage: _abs_difference(x, y) and returns: unknown