input: Write a function to count the frequency of elements in a list using collections.Counter.
  assert count_frequency(['a', 'b', 'c', 'a', 'c', 'b', 'd', 'd']) == {'a': 2, 'b': 2, 'c': 2, 'd': 2}
  assert count_frequency(['x', 'y', 'z', 'x', 'x', 'y']) == {'x': 3, 'y': 2, 'z': 1}
  assert count_frequency(['p', 'q', 'p', 'r', 'p', 'q']) == {'p': 3, 'q': 2, 'r': 1}
output: from collections import Counter
  
  def count_frequency(lst):
      return dict(Counter(lst))