src/transformers/models/layoutlm/configuration_layoutlm.py/LayoutLMOnnxConfig/__init__
class LayoutLMOnnxConfig:    def __init__(
        self,
        config: PretrainedConfig,
        task: str = "default",
        patching_specs: List[PatchingSpec] = None,
    ):
        super().__init__(config, task=task, patching_specs=patching_specs)
        self.max_2d_positions = config.max_2d_position_embeddings - 1