code: def fake_metric(y_hat, y):
      return (y_hat - y).mean()
  
file_path: pytorch_tabular/tests/test_categorical_embedding.py
imports: import numpy
  import pytest
  import torch
  from pytorch_tabular import TabularModel
  from pytorch_tabular.categorical_encoders import CategoricalEmbeddingTransformer
  from pytorch_tabular.config import DataConfig, OptimizerConfig, TrainerConfig
  from pytorch_tabular.models import CategoryEmbeddingModelConfig
  from sklearn.preprocessing import PowerTransformer
label_desc: Use image node_id 1 for calling a global function with example usage: fake_metric(y_hat, y) and returns: unknown