input: Write a python function to count occurrences of a given element in a list.
  assert count_element([1, 2, 3, 2, 4, 2, 5], 2) == 3
  assert count_element(['a', 'b', 'a', 'c', 'a', 'd'], 'a') == 3
  assert count_element([1, 1, 1, 1, 1], 1) == 5
output: def count_element(lst, element):
      return lst.count(element)