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diff --git a/common/src/com/android/tv/common/util/CollectionUtils.java b/common/src/com/android/tv/common/util/CollectionUtils.java
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+++ b/common/src/com/android/tv/common/util/CollectionUtils.java
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+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * 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.android.tv.common.util;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
+
+/** Static utilities for collections */
+public class CollectionUtils {
+
+    /**
+     * Returns an array with the arrays concatenated together.
+     *
+     * @see <a href="http://stackoverflow.com/a/784842/1122089">Stackoverflow answer</a> by <a
+     *     href="http://stackoverflow.com/users/40342/joachim-sauer">Joachim Sauer</a>
+     */
+    public static <T> T[] concatAll(T[] first, T[]... rest) {
+        int totalLength = first.length;
+        for (T[] array : rest) {
+            totalLength += array.length;
+        }
+        T[] result = Arrays.copyOf(first, totalLength);
+        int offset = first.length;
+        for (T[] array : rest) {
+            System.arraycopy(array, 0, result, offset, array.length);
+            offset += array.length;
+        }
+        return result;
+    }
+
+    /**
+     * Unions the two collections and returns the unified list.
+     *
+     * <p>The elements is not compared with hashcode() or equals(). Comparator is used for the
+     * equality check.
+     */
+    public static <T> List<T> union(
+            Collection<T> originals, Collection<T> toAdds, Comparator<T> comparator) {
+        List<T> result = new ArrayList<>(originals);
+        Collections.sort(result, comparator);
+        List<T> resultToAdd = new ArrayList<>();
+        for (T toAdd : toAdds) {
+            if (Collections.binarySearch(result, toAdd, comparator) < 0) {
+                resultToAdd.add(toAdd);
+            }
+        }
+        result.addAll(resultToAdd);
+        return result;
+    }
+
+    /** Subtracts the elements from the original collection. */
+    public static <T> List<T> subtract(
+            Collection<T> originals, T[] toSubtracts, Comparator<T> comparator) {
+        List<T> result = new ArrayList<>(originals);
+        Collections.sort(result, comparator);
+        for (T toSubtract : toSubtracts) {
+            int index = Collections.binarySearch(result, toSubtract, comparator);
+            if (index >= 0) {
+                result.remove(index);
+            }
+        }
+        return result;
+    }
+
+    /** Returns {@code true} if the two specified collections have common elements. */
+    public static <T> boolean containsAny(
+            Collection<T> c1, Collection<T> c2, Comparator<T> comparator) {
+        List<T> contains = new ArrayList<>(c1);
+        Collections.sort(contains, comparator);
+        for (T iterate : c2) {
+            if (Collections.binarySearch(contains, iterate, comparator) >= 0) {
+                return true;
+            }
+        }
+        return false;
+    }
+}