code: def preprocess():
      text = "Here is some text to encode : Hello World"
      tokens = tokenizer.encode(text)
      tokens = np.array(tokens)
      return tokens.reshape([1, 1, -1]).astype(np.float32)
  
file_path: singa/examples/onnx/gpt2/gpt2.py
imports: import os
  import numpy
  from singa import device
  from singa import tensor
  from singa import sonnx
  from singa import autograd
  import onnx
  import sys
  from utils import download_model
  import logging
  from transformers import GPT2Tokenizer
label_desc: Use image node_id 1 for calling a global function with example usage: preprocess() and returns: tokens