n head on top (linear layer).
    [`OpenAIGPTForSequenceClassification`] uses the last token in order to do the classification, as other causal
    models (e.g. GPT-2) do. Since it does classification on the last token, it requires to know the position of the
    last token. If a `pad_token_id` is defined in the configuration, it finds the last token that is not a padding
    token in each row. If no `pad_token_id` is defined, it simply takes the last value in each row of the batch. Since
    it cannot guess the padding tokens when `inputs_embeds` are passed instead of `input_ids`, it does the same (take
    the last value in each row of the batch).
    c