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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def register_model(model_name, dataset_name, model_func):
 """Register a new model that can be obtained with `get_model_config`."""

    model_map = _get_model_map(dataset_name)
    if model_name in model_map:
        raise ValueError("Model \"%s\" is already registered for dataset"
                         "\"%s\"" % (model_name, dataset_name))
    model_map[model_name] = model_func