input: Write a python function to analyze a document and return the word frequencies using collections.Counter.
  assert analyze_document("hello world hello") == [('hello', 2), ('world', 1)]
  assert analyze_document("test test test case case") == [('test', 3), ('case', 2)]
  assert analyze_document("a b c d e f g h i j") == [('a', 1), ('b', 1), ('c', 1), ('d', 1), ('e', 1), ('f', 1), ('g', 1), ('h', 1), ('i', 1), ('j', 1)]
output: def analyze_document(text):
      from collections import Counter
      word_counts = Counter(text.split())
      return list(word_counts.items())