input: Write a function to determine if the first string contains the second string. If it does, return True, otherwise return False. If either string is empty, return False.
  
  assert check_contains('catering', 'cat') == True
  assert check_contains('banana', 'ana') == True
  assert check_contains('apple', 'pie') == False
  assert check_contains('sun', '') == False
  assert check_contains('', 'moon') == False
output: def check_contains(s1, s2):
      if not s1 or not s2:
          return False
      return s2 in s1