From cba4695a60de7ee709b060af2258e4e53c39652f Mon Sep 17 00:00:00 2001
From: xhh <xhh@xhh.me>
Date: Mon, 21 Sep 2015 10:51:34 +0800
Subject: [PATCH] Add null-checking to addRequired

---
 .../src/main/java/io/swagger/models/ModelImpl.java           | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/modules/swagger-models/src/main/java/io/swagger/models/ModelImpl.java b/modules/swagger-models/src/main/java/io/swagger/models/ModelImpl.java
index d273e58373..75f57fc98f 100644
--- a/modules/swagger-models/src/main/java/io/swagger/models/ModelImpl.java
+++ b/modules/swagger-models/src/main/java/io/swagger/models/ModelImpl.java
@@ -140,7 +140,10 @@ public void setFormat(String format) {
     }
 
     public void addRequired(String name) {
-        this.required.add(name);
+        if (required == null) {
+            required = new ArrayList<String>();
+        }
+        required.add(name);
         Property p = properties.get(name);
         if (p != null) {
             p.setRequired(true);