input: Write a python function to count the occurrences of each word in a given phrase.
  assert word_count("hello world hello") == {"hello": 2, "world": 1}
  assert word_count("test the function test the code") == {"test": 2, "the": 2, "function": 1, "code": 1}
  assert word_count("one two three two three three") == {"one": 1, "two": 2, "three": 3}
output: def word_count(phrase):
      words = phrase.split()
      count_dict = {}
      for word in words:
          if word in count_dict:
              count_dict[word] += 1
          else:
              count_dict[word] = 1
      return count_dict