Minor refactorings and code style changes. 1) Removed several use of raw types 2) Removed unnecessary throws clauses 3) Used lambda expressions wherever applicable 4) Used apt assertion methods for readability 5) Use of try with resources wherever applicable 6) Corrected incorrect order of assertXXX arguments

null-object/src/test/java/com/iluwatar/nullobject/NullNodeTest.java

@@ -56,7 +56,7 @@ public class NullNodeTest {
   }
 
   @Test
-  public void testWalk() throws Exception {
+  public void testWalk() {
     NullNode.getInstance().walk();
   }
 

null-object/src/test/java/com/iluwatar/nullobject/TreeTest.java

@@ -110,7 +110,7 @@ public class TreeTest {
   }
 
   @Test
-  public void testGetLeft() throws Exception {
+  public void testGetLeft() {
     final Node level1 = TREE_ROOT.getLeft();
     assertNotNull(level1);
     assertEquals("level1_a", level1.getName());
@@ -130,7 +130,7 @@ public class TreeTest {
   }
 
   @Test
-  public void testGetRight() throws Exception {
+  public void testGetRight() {
     final Node level1 = TREE_ROOT.getRight();
     assertNotNull(level1);
     assertEquals("level1_b", level1.getName());