input: Write a python function to find the first sublist whose sum is divisible by 7.
  assert find_sublist_divisible_by_7([1, 2, 3, 4, 5, 6, 7]) == [7]
  assert find_sublist_divisible_by_7([1, 2, 3, 4, 5, 6]) == [1, 2, 3, 4, 5, 6]
  assert find_sublist_divisible_by_7([1, 2, 3, 4, 5, 6, 8]) == [1, 2, 3, 4, 5, 6]
  assert find_sublist_divisible_by_7([3, 4, 2, 1, 9, 7]) == [3, 4]
output: def find_sublist_divisible_by_7(lst):
      n = len(lst)
      for i in range(n):
          for j in range(i, n):
              sublist = lst[i:j+1]
              if sum(sublist) % 7 == 0:
                  return sublist
      return []