| /* |
| * Copyright 2000-2009 JetBrains s.r.o. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package com.intellij.openapi.vcs.impl; |
| |
| import org.jetbrains.annotations.Nullable; |
| |
| import java.util.Collection; |
| import java.util.HashSet; |
| import java.util.Set; |
| |
| public class CollectionsDelta { |
| private CollectionsDelta() { |
| } |
| |
| @Nullable |
| public static <T> Set<T> notInSecond(final Collection<T> first, final Collection<T> second) { |
| Set<T> notInSecond = null; |
| for (T topItem : first) { |
| if (! second.contains(topItem)) { |
| if (notInSecond == null) { |
| notInSecond = new HashSet<T>(); |
| } |
| notInSecond.add(topItem); |
| } |
| } |
| return notInSecond; |
| } |
| } |