code: def get_pairs(word):
      """Return set of symbol pairs in a word.
  
      Word is represented as tuple of symbols (symbols being variable-length strings).
      """
      pairs = set()
      prev_char = word[0]
      for char in word[1:]:
          pairs.add((prev_char, char))
          prev_char = char
      return pairs
  
file_path: gpt-2-simple/gpt_2_simple/src/encoder.py
imports: import os
  import json
  import regex
  from functools import lru_cache
label_desc: Use image node_id 2 for calling a global function with example usage: get_pairs(word) and returns: pairs