Java Utililty Methods Map Merge

Map<K, V> result = new LinkedHashMap<>(into.size() + with.size());
result.putAll(into);
result.putAll(with);
return result;

Map<K, V> resultMap = new HashMap<K, V>();
resultMap.putAll(left);
resultMap.putAll(right);
return resultMap;

map.put(key, value);
return map;

if (maps != null && maps.length > 0) {
    for (Map<K, V> m : maps)
        map.putAll(m);
return map;

copy.putAll(master);

if (src == null || src.size() == 0) {
    return dest;
if (dest == null || dest.size() == 0) {
    return src;
Map<String, Object> result = new HashMap<>();
src.forEach((key, value) -> {
...

if (second == null || second.isEmpty())
    return first;
if (first == null || first.isEmpty())
    return second;
Map<String, Object> combined = new HashMap<>(first);
combined.putAll(second);
return combined;

Map<T1, T3> map3 = new HashMap<T1, T3>(map1.size());
merge(map1, map2, map3);
return map3;

Map<T1, T2> newMap = new HashMap<>();
for (Map.Entry<T1, T2> entry : mapPriorityLeast.entrySet()) {
    newMap.put(entry.getKey(), entry.getValue());
for (Map.Entry<T1, T2> entry : mapPriorityFirst.entrySet()) {
    newMap.put(entry.getKey(), entry.getValue());
return newMap;
...

Map<String, Object> ret = new HashMap<>();
Integer numExecutors = getByKeyOr0(accSpoutStats, NUM_EXECUTORS).intValue();
putKV(ret, NUM_EXECUTORS, numExecutors + 1);
putKV(ret, NUM_TASKS, sumOr0(getByKeyOr0(accSpoutStats, NUM_TASKS), getByKeyOr0(spoutStats, NUM_TASKS)));
putKV(ret, EMITTED, sumOr0(getByKeyOr0(accSpoutStats, EMITTED), getByKeyOr0(spoutStats, EMITTED)));
putKV(ret, TRANSFERRED,
        sumOr0(getByKeyOr0(accSpoutStats, TRANSFERRED), getByKeyOr0(spoutStats, TRANSFERRED)));
putKV(ret, COMP_LAT_TOTAL,
...