chunked/nltk_chunking/model_doc_bert-generation/chunk_12.txt

", add_special_tokens=False, return_tensors="pt"
 ).input_ids
outputs = sentence_fuser.generate(input_ids)
print(tokenizer.decode(outputs[0]))

Tips:

[BertGenerationEncoder] and [BertGenerationDecoder] should be used in
  combination with [EncoderDecoder].