docs: update .all-contributorsrc [skip ci]

.all-contributorsrc

@@ -1577,15 +1577,6 @@
       "contributions": [
         "code"
       ]
-    },
-    {
-      "login": "mortezaadi",
-      "name": "Morteza Adigozalpour",
-      "avatar_url": "https://avatars.githubusercontent.com/u/1329687?v=4",
-      "profile": "https://github.com/mortezaadi",
-      "contributions": [
-        "code"
-      ]
     }
   ],
   "contributorsPerLine": 4,

README.md

@@ -10,7 +10,7 @@
 [![Coverage](https://sonarcloud.io/api/project_badges/measure?project=iluwatar_java-design-patterns&metric=coverage)](https://sonarcloud.io/dashboard?id=iluwatar_java-design-patterns)
 [![Join the chat at https://gitter.im/iluwatar/java-design-patterns](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/iluwatar/java-design-patterns?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-174-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-173-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 <br/>
@@ -335,7 +335,6 @@ This project is licensed under the terms of the MIT license.
   </tr>
   <tr>
     <td align="center"><a href="https://github.com/karthikbhat13"><img src="https://avatars.githubusercontent.com/u/22431014?v=4?s=100" width="100px;" alt=""/><br /><sub><b>karthikbhat13</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=karthikbhat13" title="Code">💻</a></td>
-    <td align="center"><a href="https://github.com/mortezaadi"><img src="https://avatars.githubusercontent.com/u/1329687?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Morteza Adigozalpour</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=mortezaadi" title="Code">💻</a></td>
   </tr>
 </table>
 

singleton/src/main/java/com/iluwatar/singleton/ThreadSafeDoubleCheckLocking.java

@@ -36,12 +36,16 @@ public final class ThreadSafeDoubleCheckLocking {
 
   private static volatile ThreadSafeDoubleCheckLocking instance;
 
+  private static boolean flag = true;
+
   /**
    * private constructor to prevent client from instantiating.
    */
   private ThreadSafeDoubleCheckLocking() {
     // to prevent instantiating by Reflection call
-    if (instance != null) {
+    if (flag) {
+      flag = false;
+    } else {
       throw new IllegalStateException("Already initialized.");
     }
   }

singleton/src/main/java/com/iluwatar/singleton/ThreadSafeLazyLoadedIvoryTower.java

@@ -34,7 +34,9 @@ public final class ThreadSafeLazyLoadedIvoryTower {
 
   private ThreadSafeLazyLoadedIvoryTower() {
     // Protect against instantiation via reflection
-    if (instance != null) {
+    if (instance == null) {
+      instance = this;
+    } else {
       throw new IllegalStateException("Already initialized.");
     }
   }