input: Write a python function to convert a word to lowercase using a lambda function.
  assert change_word_to_lowercase("CHANGE") == "change"
  assert change_word_to_lowercase("Python") == "python"
  assert change_word_to_lowercase("HeLLo") == "hello"
output: def change_word_to_lowercase(word):
      to_lowercase = lambda x: x.lower()
      return to_lowercase(word)