vcs-impl/src/com/intellij/openapi/vcs/impl/CollectionsDelta.java

   1 package com.intellij.openapi.vcs.impl;
   2
   3 import org.jetbrains.annotations.Nullable;
   4
   5 import java.util.Collection;
   6 import java.util.HashSet;
   7 import java.util.Set;
   8
   9 public class CollectionsDelta {
  10   private CollectionsDelta() {
  11   }
  12
  13   @Nullable
  14   public static <T> Set<T> notInSecond(final Collection<T> first, final Collection<T> second) {
  15     Set<T> notInSecond = null;
  16     for (T topItem : first) {
  17       if (! second.contains(topItem)) {
  18         if (notInSecond == null) {
  19           notInSecond = new HashSet<T>();
  20         }
  21         notInSecond.add(topItem);
  22       }
  23     }
  24     return notInSecond;
  25   }
  26 }