1 files changed, 8 insertions, 0 deletions
diff --git a/java/src/com/android/inputmethod/latin/NgramContext.java b/java/src/com/android/inputmethod/latin/NgramContext.java
index 2dc409f9f..0ccea4732 100644
--- a/java/src/com/android/inputmethod/latin/NgramContext.java
+++ b/java/src/com/android/inputmethod/latin/NgramContext.java
@@ -19,17 +19,22 @@ package com.android.inputmethod.latin;
 import android.text.TextUtils;
 
 import com.android.inputmethod.annotations.UsedForTesting;
+import com.android.inputmethod.latin.common.Constants;
 import com.android.inputmethod.latin.utils.StringUtils;
 
 import java.util.Arrays;
 
+import javax.annotation.Nonnull;
+
 /**
  * Class to represent information of previous words. This class is used to add n-gram entries
  * into binary dictionaries, to get predictions, and to get suggestions.
  */
 public class NgramContext {
+    @Nonnull
     public static final NgramContext EMPTY_PREV_WORDS_INFO =
             new NgramContext(WordInfo.EMPTY_WORD_INFO);
+    @Nonnull
     public static final NgramContext BEGINNING_OF_SENTENCE =
             new NgramContext(WordInfo.BEGINNING_OF_SENTENCE_WORD_INFO);
 
@@ -37,7 +42,9 @@ public class NgramContext {
      * Word information used to represent previous words information.
      */
     public static class WordInfo {
+        @Nonnull
         public static final WordInfo EMPTY_WORD_INFO = new WordInfo(null);
+        @Nonnull
         public static final WordInfo BEGINNING_OF_SENTENCE_WORD_INFO = new WordInfo();
 
         // This is an empty char sequence when mIsBeginningOfSentence is true.
@@ -97,6 +104,7 @@ public class NgramContext {
     }
 
     // Create next prevWordsInfo using current prevWordsInfo.
+    @Nonnull
     public NgramContext getNextNgramContext(final WordInfo wordInfo) {
         final int nextPrevWordCount = Math.min(Constants.MAX_PREV_WORD_COUNT_FOR_N_GRAM,
                 mPrevWordsCount + 1);