Updated Lang3Utils.java (#2584)

* Updated Lang3Utils.java

Added a new test for ConcurrentException and updated other exception with Lambda

* LazyInitializer sample files

* Updated file with LazyInitializer Unit Test

libraries/src/main/java/com/baeldung/commons/lang3/SampleLazyInitializer.java

@@ -0,0 +1,11 @@
+package com.baeldung.commons.lang3;
+
+import org.apache.commons.lang3.concurrent.LazyInitializer;
+
+public class SampleLazyInitializer extends LazyInitializer<SampleObject> {
+    
+    @Override
+    protected SampleObject initialize() {
+        return new SampleObject();
+    }
+}

libraries/src/main/java/com/baeldung/commons/lang3/SampleObject.java

@@ -0,0 +1,7 @@
+package com.baeldung.commons.lang3;
+
+public class SampleObject {
+    
+    //Ignored
+
+}