In Java run through Eclipse

/** * * Reverses (i.e. exchanges the keys and values) a hashmap which * may contain multiple keys with the same value. Because of this, * the values of the reversed map will be a list. * * * For example: * {1=A,2=A,3=B} yields {A=[1,2], B=[3]} * * The initial hashmap maps Integers to Strings. * The reversed hashmap will map Strings to ArrayLists of Integers. * * @param initialMap the HashMap to be reversed * @return a copy of the hashmap with keys and values exchanged */ public static HashMap> reverseHashmap(HashMap initialMap) { return null; }