Java Utililty Methods List Merge

StringBuilder builder = new StringBuilder();
for (String s : text) {
    builder.append(s);
return builder.toString();

if (a == null && b == null)
    return null;
else if (a == null)
    return new ArrayList<>(b);
else if (b == null)
    return new ArrayList<>(a);
ArrayList<T> al = new ArrayList<>(a.size() + b.size());
al.addAll(a);
...

b.addAll(a);
b.sort(comp);

Collections.sort(list);

int n = list.size();
if (0 < split && split < n) {
    merge(list, 0, split, n - 1, (int) Math.sqrt(split), 0);

if (list != null) {
    if (items != null) {
        for (T item : items) {
            if (!list.contains(item)) {
                list.add(item);
} else {
    return items;
return list;

return merge(Arrays.asList(list));

list1.removeAll(list2);
list1.addAll(list2);
return list1;

while (z < y && y <= yn) {
    int j = z + indexOfMin(A.subList(z, y));
    if (A.get(j).compareTo(A.get(y)) <= 0) {
        Collections.swap(A, z, j);
    } else {
        Collections.swap(A, z, y);
        y++;
    z++;
if (z < y) {
    Collections.sort(A.subList(z, yn + 1));

int len = 0;
for (byte[] aPackage : packages) {
    len += aPackage.length;
byte[] result = new byte[len];
int pos = 0;
for (byte[] aPackage : packages) {
    for (int j = 0; j < aPackage.length; j++) {
...