code: def prepare_env():
      vocab = Vocabulary().add_word_lst("This is a test .".split())
      vocab.add_word_lst("Another test !".split())
      embed = StaticEmbedding(
          vocab, model_dir_or_name=None, embedding_dim=5
      )
  
      encoder_output = torch.randn(2, 3, 10)
      src_seq_len = torch.LongTensor([3, 2])
      encoder_mask = seq_len_to_mask(src_seq_len)
  
      return embed, encoder_output, encoder_mask
  
file_path: fastNLP/tests/modules/torch/generator/test_seq2seq_generator.py
imports: import pytest
  from fastNLP.envs.imports import _NEED_IMPORT_TORCH
label_desc: Use image node_id 1 for calling a global function with example usage: prepare_env() and returns: embed,  encoder_output,  encoder_mask