code: def process_vocab(vocab_file_path, data, vocab, min_frequency=0):
      """Process vocab"""
      for line in data:
          for word in line.split():
              vocab.add(word)
      if min_frequency > 0:
          vocab.trim(min_frequency)
      save_vocabs(vocab.mapping, vocab_file_path)
  
file_path: delta/delta/data/preprocess/utils.py
imports: import os
  import pickle
  import collections
  import numpy
  from absl import logging
  import delta.compat
  from delta.data.utils.vocabulary import Vocabulary
label_desc: Use image node_id 2 for calling a global function with example usage: process_vocab(vocab_file_path, data, vocab, min_frequency) without return types