input: Write a function to get the third largest element in a given row. If the given row has fewer than three elements, return `None`. The function should return an integer or `None`.
  assert third_largest([12, 13, 13, 45, 22, 99])==22
  assert third_largest([1, 2, 3])==1
  assert third_largest([1, 2])==None
  assert third_largest([1, 2, 3, 4, 5, 6])==4
output: def third_largest(row):
      if len(row) < 3:
          return None
      unique_sorted = sorted(set(row), reverse=True)
      if len(unique_sorted) < 3:
          return None
      return unique_sorted[2]