input: Write a python function to check if two given strings are anagrams.
  assert isAnagram("listen", "silent") == True
  assert isAnagram("hello", "billion") == False
  assert isAnagram("conversation", "voices rant on") == True
  assert isAnagram("rail safety", "fairy tales") == True
output: def isAnagram(str1, str2):
      # Remove spaces and convert to lowercase
      str1 = str1.replace(" ", "").lower()
      str2 = str2.replace(" ", "").lower()
      
      # Check if sorted characters of both strings are equal
      return sorted(str1) == sorted(str2)