From c265a9b2c6985f4e56d207e5edf407aed62ccee3 Mon Sep 17 00:00:00 2001
From: Konstantin Bulenkov <kb@jetbrains.com>
Date: Wed, 7 Dec 2011 05:06:13 +0100
Subject: [PATCH] +intersection

---
 .../com/intellij/util/containers/ContainerUtil.java   | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/platform/util/src/com/intellij/util/containers/ContainerUtil.java b/platform/util/src/com/intellij/util/containers/ContainerUtil.java
index 3e1c6ddd82e5..01916d3e999c 100644
--- a/platform/util/src/com/intellij/util/containers/ContainerUtil.java
+++ b/platform/util/src/com/intellij/util/containers/ContainerUtil.java
@@ -646,6 +646,17 @@ public class ContainerUtil {
     return false;
   }
 
+  @NotNull
+  public static <T> Collection<T> intersection(@NotNull Collection<? extends T> collection1, @NotNull Collection<? extends T> collection2) {
+    ArrayList<T> result = new ArrayList<T>();
+    for (T t : collection1) {
+      if (collection2.contains(t)) {
+        result.add(t);
+      }
+    }
+    return result;
+  }
+
   @Nullable
   public static <T> T getFirstItem(final Collection<T> items) {
     return getFirstItem(items, null);