def METHOD_NAME(items):
    """Mark tests into whether they are core-mdf or they require specific backends to be installed."""
    for item in items:
        for pattern, marker in backend_markers.items():
            # Mark any test of an example that is in a backend folder as requiring that backend.
            if "tests/test_examples.py" in item.nodeid and pattern in item.nodeid:
                item.add_marker(pytest.mark.__getattr__(marker))
                break
            # Mark any test that is under interfaces with the appropriate backend.
            elif "tests/interfaces" in item.nodeid and marker in item.nodeid:
                item.add_marker(pytest.mark.__getattr__(marker))
                break
        # These are a couple examples that should probably be under PyTorch but are in the MDF folder
        if "abcd_torch.py" in item.nodeid or "rnn_pytorch.py" in item.nodeid:
            item.add_marker(pytest.mark.pytorch)
        # For some reason there are a bunch of examples in examples/ONNX that require pytorch. These
        # should probably be rewritten to not use ONNX or moved to examples/PyTorch/ONNX or something.
        if "tests/test_examples.py" in item.nodeid and "ONNX" in item.nodeid:
            item.add_marker(pytest.mark.pytorch)
        # All other tests should be marked core MDF by default if they don't have another backend marker.
        # Remember, some tests could be marked manually and not above.
        if (
            len([m for m in item.iter_markers() if m.name in backend_markers.values()])
            == 0
        ):
            item.add_marker(pytest.mark.coremdf)