input: Write a python function to find the most common element in a list using the Counter class from the collections module.
  assert most_common([1, 2, 2, 3, 3, 3, 4, 4, 4, 4]) == 4
  assert most_common(['a', 'b', 'b', 'c', 'c', 'c', 'd']) == 'c'
  assert most_common([1, 1, 1, 2, 2, 2, 3, 3]) == 1
output: from collections import Counter
  
  def most_common(lst):
      return Counter(lst).most_common(1)[0][0]