From a855c0284c3b285dd8a71b57ec35702995ae5b30 Mon Sep 17 00:00:00 2001
From: shedaniel <daniel@shedaniel.me>
Date: Sat, 11 Jan 2020 00:34:07 +0800
Subject: 3.3.7

---
 src/main/java/me/shedaniel/rei/utils/CollectionUtils.java | 8 ++++++++
 1 file changed, 8 insertions(+)

(limited to 'src/main/java/me/shedaniel/rei/utils/CollectionUtils.java')

diff --git a/src/main/java/me/shedaniel/rei/utils/CollectionUtils.java b/src/main/java/me/shedaniel/rei/utils/CollectionUtils.java
index 296c9c747..44d6f5f6d 100644
--- a/src/main/java/me/shedaniel/rei/utils/CollectionUtils.java
+++ b/src/main/java/me/shedaniel/rei/utils/CollectionUtils.java
@@ -16,6 +16,14 @@ import java.util.function.Predicate;
 
 @Internal
 public class CollectionUtils {
+    public static <A, B> List<B> getOrPutEmptyList(Map<A, List<B>> map, A key) {
+        List<B> b = map.get(key);
+        if (b != null)
+            return b;
+        map.put(key, Lists.newArrayList());
+        return map.get(key);
+    }
+    
     public static <T> T findFirstOrNullEquals(List<T> list, T obj) {
         for (T t : list) {
             if (t.equals(obj))
-- 
cgit