<BUG>public <T extends OffsettedItem> T intern(T item) {</BUG><CONTEXT>} catch (NullPointerException ex) {throw new NullPointerException("item == null");}items.add(item);}<extra_id_0>throwIfPrepared();OffsettedItem result = interns.get(item);if (result != null) {</CONTEXT>
public synchronized <T extends OffsettedItem> T intern(T item) {