import java.util.HashMap;
import java.util.Map;
class Container {
private final Map<String, Integer> values = new HashMap<String, Integer>();
int inc(String id, int amount) {
Integer counter = values.get(id);
if (counter == null) {
counter = 0;
}
counter += amount;
values.put(id, counter);
return counter;
}
void clear() {
values.clear();
}
void applyMigrationData(Map<String, Integer> migrationData) {
values.putAll(migrationData);
}
Map<String, Integer> toMigrationData() {
return new HashMap<String, Integer>(values);
}
void init(String objectName) {
values.put(objectName, 0);
}
void destroy(String objectName) {
values.remove(objectName);
}
}