docs: add lazy loading docs + refactor (#2939)

lazy-loading/src/test/java/com/iluwatar/lazy/loading/AbstractHolderTest.java

@@ -51,13 +51,13 @@ public abstract class AbstractHolderTest {
    *
    * @return The lazy loaded {@link Heavy} object
    */
-  abstract Heavy getHeavy() throws Exception;
+  abstract Heavy getHeavy();
 
   /**
    * This test shows that the heavy field is not instantiated until the method getHeavy is called
    */
   @Test
-  void testGetHeavy() throws Exception {
+  void testGetHeavy() {
     assertTimeout(ofMillis(3000), () -> {
       assertNull(getInternalHeavyValue());
       assertNotNull(getHeavy());

lazy-loading/src/test/java/com/iluwatar/lazy/loading/HolderNaiveTest.java

@@ -24,8 +24,6 @@
  */
 package com.iluwatar.lazy.loading;
 
-import java.lang.reflect.Field;
-
 /**
  * Date: 12/19/15 - 12:05 PM
  *

lazy-loading/src/test/java/com/iluwatar/lazy/loading/HolderThreadSafeTest.java

@@ -24,8 +24,6 @@
  */
 package com.iluwatar.lazy.loading;
 
-import java.lang.reflect.Field;
-
 /**
  * Date: 12/19/15 - 12:19 PM
  *
@@ -43,7 +41,7 @@ class HolderThreadSafeTest extends AbstractHolderTest {
   }
 
   @Override
-  Heavy getHeavy() throws Exception {
+  Heavy getHeavy() {
     return this.holder.getHeavy();
   }
 

lazy-loading/src/test/java/com/iluwatar/lazy/loading/Java8HolderTest.java

@@ -24,7 +24,6 @@
  */
 package com.iluwatar.lazy.loading;
 
-import java.lang.reflect.Field;
 import java.util.function.Supplier;
 
 /**
@@ -57,7 +56,7 @@ class Java8HolderTest extends AbstractHolderTest {
   }
 
   @Override
-  Heavy getHeavy() throws Exception {
+  Heavy getHeavy() {
     return holder.getHeavy();
   }