input: Write a python function to find the longest word in a given text.
  assert find_longest_word("This is an example of a sample text.") == "example"
  assert find_longest_word("Python programming is fun") == "programming"
  assert find_longest_word("A quick brown fox jumps over the lazy dog") == "jumps"
output: def find_longest_word(text):
      words = text.split()
      longest_word = max(words, key=len)
      return longest_word