src/transformers/models/perceiver/modeling_perceiver.py/PerceiverMultimodalPostprocessor/__init__
class PerceiverMultimodalPostprocessor:    def __init__(self, modalities: Mapping[str, PostprocessorType], input_is_dict: bool = False):
        super().__init__()
        self.modalities = nn.ModuleDict(modalities)
        self.input_is_dict = input_is_dict