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

    Return set of symbol pairs in a word.
    word is represented as tuple of symbols (symbols being variable-length strings)
    
xtune/src/transformers/tokenization_xlm.py