src/transformers/models/clip/tokenization_clip.py/CLIPTokenizer/prepare_for_tokenization
class CLIPTokenizer:    def prepare_for_tokenization(self, text, is_split_into_words=False, **kwargs):
        add_prefix_space = kwargs.pop("add_prefix_space", self.add_prefix_space)
        if is_split_into_words or add_prefix_space:
            text = " " + text
        return (text, kwargs)