input: Write a python function to find the most common items in a list using the Counter class from collections module.
  assert most_common_items([1, 2, 3, 4, 5, 6, 7, 2, 2, 2, 2, 8, 8, 8, 8, 9, 9, 9]) == [(2, 4), (8, 4), (9, 3), (1, 1), (3, 1), (4, 1), (5, 1), (6, 1), (7, 1)]
  assert most_common_items([1, 1, 1, 1, 2, 2, 2, 3, 3, 4]) == [(1, 4), (2, 3), (3, 2), (4, 1)]
  assert most_common_items([]) == []
output: def most_common_items(lst):
      from collections import Counter
      return Counter(lst).most_common()