Write the method: public static String doubleVowels(String x). This method takes a String x and returns a new String y which is identical to x except wherever there is a vowel in x, there will be two of that same vowel in the returned String y. The original String x will contain only lower case letters.

For example, doubleVowels("easy") should return the String "eeaasy". Another example: doubleVowels("abootstrap") should return the String "aabooootstraap". Another example: doubleVowels("gggrrrhh") should return the String "gggrrrhh".

public static String doubleValue(String x) {