diff --git a/common/src/com/android/inputmethod/latin/common/CollectionUtils.java b/common/src/com/android/inputmethod/latin/common/CollectionUtils.java
index f7ba693..48df413 100644
--- a/common/src/com/android/inputmethod/latin/common/CollectionUtils.java
+++ b/common/src/com/android/inputmethod/latin/common/CollectionUtils.java
@@ -16,6 +16,8 @@
 
 package com.android.inputmethod.latin.common;
 
+import com.android.inputmethod.annotations.UsedForTesting;
+
 import java.util.ArrayList;
 import java.util.Collection;
 
@@ -57,6 +59,7 @@
      * @param c Collection to test.
      * @return Whether c contains no elements.
      */
+    @UsedForTesting
     public static boolean isNullOrEmpty(@Nullable final Collection<?> c) {
         return c == null || c.isEmpty();
     }
diff --git a/common/src/com/android/inputmethod/latin/common/InputPointers.java b/common/src/com/android/inputmethod/latin/common/InputPointers.java
index 7beee15..4b2ae7e 100644
--- a/common/src/com/android/inputmethod/latin/common/InputPointers.java
+++ b/common/src/com/android/inputmethod/latin/common/InputPointers.java
@@ -112,6 +112,7 @@
      * Shift to the left by elementCount, discarding elementCount pointers at the start.
      * @param elementCount how many elements to shift.
      */
+    @UsedForTesting
     public void shift(final int elementCount) {
         mXCoordinates.shift(elementCount);
         mYCoordinates.shift(elementCount);
diff --git a/common/src/com/android/inputmethod/latin/common/ResizableIntArray.java b/common/src/com/android/inputmethod/latin/common/ResizableIntArray.java
index 340abb2..77f5c4c 100644
--- a/common/src/com/android/inputmethod/latin/common/ResizableIntArray.java
+++ b/common/src/com/android/inputmethod/latin/common/ResizableIntArray.java
@@ -16,6 +16,8 @@
 
 package com.android.inputmethod.latin.common;
 
+import com.android.inputmethod.annotations.UsedForTesting;
+
 import java.util.Arrays;
 
 import javax.annotation.Nonnull;
@@ -140,6 +142,7 @@
      * Shift to the left by elementCount, discarding elementCount pointers at the start.
      * @param elementCount how many elements to shift.
      */
+    @UsedForTesting
     public void shift(final int elementCount) {
         System.arraycopy(mArray, elementCount, mArray, 0, mLength - elementCount);
         mLength -= elementCount;