input: Write a function to check if two given strings are anagrams of each other. If they are anagrams, return True; otherwise, return False. If either of the strings is empty, return False.
  assert is_anagram("abcd", "cbda")==True
  assert is_anagram("abcd", "edba")==False
  assert is_anagram("listen", "silent")==True
  assert is_anagram("", "silent")==False
  assert is_anagram("triangle", "integral")==True
output: def is_anagram(s1, s2):
      if s1 == "" or s2 == "":
          return False
      return sorted(s1) == sorted(s2)