What are the default models used for the various pipeline tasks?  I assume the “SummarizationPipeline” uses Bart-large-cnn or some variant of T5, but what about the other tasks?
|ConversationalPipeline|?|
|FeatureExtractionPipeline|?|
|FillMaskPipeline|?|
|QuestionAnsweringPipeline|?|
|SummarizationPipeline|BART or T5 (?)|
|TextClassificationPipeline|?|
|TextGenerationPipeline|?|
|TokenClassificationPipeline|?|
|TranslationPipeline|?|
|ZeroShotClassificationPipeline|?|
|Text2TextGenerationPipeline|?|