Find the ArrayList ＜ double ＞ with the most occurrences in ArrayList ＜ ArrayList ＜ double ＞

public static ArrayList<Double> candidate (ArrayList<ArrayList<Double>> list)    //  Find the number that appears the most in the array 
        {
            // map Of key Store the numbers in the array ,value Store the number of occurrences of this number 
            HashMap<ArrayList<Double>, Integer> map = new HashMap<ArrayList<Double>, Integer>();
            for(int i = 0; i < list.size(); i++)
            {
                if(map.containsKey(list.get(i)))
                {
                    int formerValue = map.get(list.get(i));
                    map.put(list.get(i), formerValue + 1);    //  The number of times this number appears plus 1
                }
                else
                {
                    map.put(list.get(i), 1);    //  This number appears for the first time 
                }
            }
            Collection<Integer> count = map.values();
            //  find map Of value The maximum , That is, the number of times that the most numbers appear in the array 
            int maxCount = Collections.max(count);
            ArrayList<Double> maxNumber = new ArrayList<>();
            for(Map.Entry<ArrayList<Double>, Integer> entry : map.entrySet())
            {
                // obtain value by maxCount Of key, That is, the number that appears the most times in the array 
                if(entry.getValue() == maxCount)
                {
                    maxNumber = entry.getKey();
                }
            }

            return maxNumber;
        }