input: Write a function to determine if two given strings are anagrams. If they are anagrams return True else return False.
  assert is_anagram("abcd", "cbda")==True
  assert is_anagram("abcd", "abce")==False
  assert is_anagram("silent", "listen")==True
  assert is_anagram("hello", "world")==False
  assert is_anagram("", "")==True
output: def is_anagram(str1, str2):
      return sorted(str1) == sorted(str2)