code: def test_combiner_schema_is_not_empty_for_ECD():
      # Essentially verifies that the combiner registry is not empty at import time:
      assert (
          len(get_schema(MODEL_ECD)["properties"]["combiner"]["allOf"])
          > 0
      )
  
file_path: ludwig/tests/ludwig/config_validation/test_validate_config_combiner.py
imports: import pytest
  from ludwig.config_validation.validation import check_schema, get_schema
  from ludwig.constants import MODEL_ECD, TRAINER
  from ludwig.error import ConfigValidationError
  from tests.integration_tests.utils import binary_feature, category_feature, number_feature
label_desc: Use image node_id 1 for calling a global function with example usage: test_combiner_schema_is_not_empty_for_ECD() without return types