Please read the following diagram carefully, and answer Question 2.1 - 2.3 java.lang > Iterable +iterator: IteratorE> ava.util > Collection Iterator thasNext0: boolean +size): int isEmpty0: boolean +next) E K IVI List Set Ma add(element: E): boolean +addfindex int, element E) boolean cleart) getindex: int) E remove(element : E) : boolean sort(c Comparator) addfejiement: E): boolean +clear) remove(element: E): boolean tclear +containsKeykey: K):booloan get(key K) V tisEmpty0: boolean tkeySet(): Set tput(key: K, value V:V remove(key: K) V treplace(key: K, value V): V size) int values): CollectioncV> HashSet HashSet) ArrayList ArrayList Link edList IVI IVI LinkedList() HashMa +HashMap0 TreeMa +TreeMap) 2.1 How many packages are in the diagram? What are they? 2.2 What doand represent respectively? What is the difference between them? 2.3 Why methods in an interface are italicized