Return a new version of the input parameter string 'str' where every vowel has been shifted to the left by one vowel position and the very first vowel has been shifted to the previous position of the last vowel. For the purpose of this method vowels are 'a', 'e', 'i', 'o', and 'u'. All input strings will contain only lower-case letters, spaces, and punctuations. For example: The string "churches float" would become "cherchos flaut". While the string "racecar" would become "recacar". Strings with no vowel or only one vowel will remain unchanged. You may use recursion or loops. You may NOT use any of the 'replace'-style string commands.