1 /* 2 * Copyright (C) 2008 The Guava Authors 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not 5 * use this file except in compliance with the License. You may obtain a copy of 6 * the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 13 * License for the specific language governing permissions and limitations under 14 * the License. 15 */ 16 17 package com.google.common.collect; 18 19 import com.google.common.annotations.GwtCompatible; 20 21 import javax.annotation.Nullable; 22 23 /** 24 * An empty immutable multiset. 25 * 26 * @author Jared Levy 27 * @author Louis Wasserman 28 */ 29 @GwtCompatible(serializable = true) 30 final class EmptyImmutableMultiset extends ImmutableMultiset<Object> { 31 static final EmptyImmutableMultiset INSTANCE = new EmptyImmutableMultiset(); 32 33 @Override count(@ullable Object element)34 public int count(@Nullable Object element) { 35 return 0; 36 } 37 38 @Override elementSet()39 public ImmutableSet<Object> elementSet() { 40 return ImmutableSet.of(); 41 } 42 43 @Override size()44 public int size() { 45 return 0; 46 } 47 48 @Override entryIterator()49 UnmodifiableIterator<Entry<Object>> entryIterator() { 50 return Iterators.emptyIterator(); 51 } 52 53 @Override distinctElements()54 int distinctElements() { 55 return 0; 56 } 57 58 @Override isPartialView()59 boolean isPartialView() { 60 return false; 61 } 62 63 @Override createEntrySet()64 ImmutableSet<Entry<Object>> createEntrySet() { 65 return ImmutableSet.of(); 66 } 67 68 private static final long serialVersionUID = 0; 69 } 70