input: Write a function to determine if two strings are anagrams of each other. If they are anagrams, return True; otherwise, return False.
  
  def is_anagram(str1, str2):
      if len(str1) != len(str2):
          return False
  
      str1_counts = collections.Counter(str1)
      str2_counts = collections.Counter(str2)
      
      for char in str1_counts:
          if str1_counts[char] != str2_counts[char]:
              return False
      return True
  
  assert is_anagram("abcd", "cbda")==True
  assert is_anagram("listen", "silent")==True
  assert is_anagram("hello", "world")==False
  assert is_anagram("", "")==True
  assert is_anagram("aabb", "abab")==True
output: def is_anagram(str1, str2):
      if len(str1) != len(str2):
          return False
  
      str1_counts = collections.Counter(str1)
      str2_counts = collections.Counter(str2)
      
      for char in str1_counts:
          if str1_counts[char] != str2_counts[char]:
              return False
      return True