input: Write a python function to check if two strings are anagrams of each other.
  assert is_anagram('listen', 'silent') == True
  assert is_anagram('hello', 'bello') == False
  assert is_anagram('evil', 'vile') == True
  assert is_anagram('cinema', 'iceman') == True
  assert is_anagram('fluster', 'restful') == True
output: def is_anagram(str1, str2):
      return sorted(str1) == sorted(str2)