// return a copy of commonContents; in theory we want a deep clone
// of commonContents, but since it only contains (immutable) Strings,
// this shallow copy is sufficient
Object[][] commonCopy = new Object[commonContents.length][2];
for (int i = 0; i < commonContents.length; i++) {
commonCopy[i][0] = commonContents[i][0];
commonCopy[i][1] = commonContents[i][1];
}
return commonCopy;