diff --git a/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/comparation/ArrayListUnitTest.java b/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/comparation/ArrayListUnitTest.java
index 935be19e74..4041ff1637 100644
--- a/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/comparation/ArrayListUnitTest.java
+++ b/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/comparation/ArrayListUnitTest.java
@@ -11,7 +11,7 @@ import static org.assertj.core.api.Assertions.assertThat;
 public class ArrayListUnitTest {
 
     @Test
-    void givenList_whenItemAddedToSpecificIndex_thenItCanBeRetrieved() {
+    void givenArrayList_whenItemAddedToSpecificIndex_thenItCanBeRetrieved() {
         List<String> list = new ArrayList<>();
         list.add("Daniel");
         list.add(1, "Marko");
@@ -20,10 +20,11 @@ public class ArrayListUnitTest {
     }
 
     @Test
-    void givenList_whenItemRemovedViaIndex_thenListSizeIsReduced() {
+    void givenArrayList_whenItemRemovedViaIndex_thenListSizeIsReduced() {
         List<String> list = new ArrayList<>(Arrays.asList("Daniel", "Marko"));
         list.remove(1);
         assertThat(list).hasSize(1);
+        assertThat(list).doesNotContain("Marko");
     }
 
 }
diff --git a/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/comparation/HashMapUnitTest.java b/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/comparation/HashMapUnitTest.java
new file mode 100644
index 0000000000..3b595472e0
--- /dev/null
+++ b/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/comparation/HashMapUnitTest.java
@@ -0,0 +1,31 @@
+package com.baeldung.collections.comparation;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.Map;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class HashMapUnitTest {
+
+    @Test
+    void givenHashMap_whenItemAddedByKey_thenItCanBeRetrieved() {
+        Map<String, String> map = new HashMap<>();
+        map.put("123456", "Daniel");
+        map.put("654321", "Marko");
+        assertThat(map.get("654321")).isEqualTo("Marko");
+    }
+
+    @Test
+    void givenHashMap_whenItemRemovedByKey_thenMapSizeIsReduced() {
+        Map<String, String> map = new HashMap<>();
+        map.put("123456", "Daniel");
+        map.put("654321", "Marko");
+        map.remove("654321");
+        assertThat(map).hasSize(1);
+    }
+
+}
diff --git a/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/comparation/LinkedListUnitTest.java b/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/comparation/LinkedListUnitTest.java
new file mode 100644
index 0000000000..c2ab554c91
--- /dev/null
+++ b/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/comparation/LinkedListUnitTest.java
@@ -0,0 +1,41 @@
+package com.baeldung.collections.comparation;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.LinkedList;
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class LinkedListUnitTest {
+
+    @Test
+    void givenLinkedList_whenItemIsAppended_thenItCanBeRetrieved() {
+        LinkedList<String> list = new LinkedList<>();
+        list.addLast("Daniel");
+        list.addFirst( "Marko");
+        assertThat(list).hasSize(2);
+        assertThat(list.getLast()).isEqualTo("Daniel");
+    }
+
+    @Test
+    void givenLinkedList_whenItemIsRemoved_thenListSizeIsReduced() {
+        LinkedList<String> list = new LinkedList<>(Arrays.asList("Daniel", "Marko", "David"));
+        list.removeFirst();
+        list.removeLast();
+        assertThat(list).hasSize(1);
+        assertThat(list).containsExactly("Marko");
+    }
+
+    @Test
+    void givenLinkedList_whenItemInserted_thenItCanBeRetrievedAndDeleted() {
+        LinkedList<String> list = new LinkedList<>();
+        list.push("Daniel");
+        list.push("Marko");
+        assertThat(list.poll()).isEqualTo("Marko");
+        assertThat(list).hasSize(1);
+    }
+
+}
diff --git a/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/comparation/ListVsMapUnitTest.java b/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/comparation/ListVsMapUnitTest.java
index 6507013fbf..dd6bf760fd 100644
--- a/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/comparation/ListVsMapUnitTest.java
+++ b/core-java-modules/core-java-collections-4/src/test/java/com/baeldung/collections/comparation/ListVsMapUnitTest.java
@@ -15,6 +15,7 @@ class ListVsMapUnitTest {
         for (String name : list) {
             assertThat(name).isIn(list);
         }
+        assertThat(list).containsExactly("Daniel", "Marko");
     }
 
     @Test
@@ -25,6 +26,7 @@ class ListVsMapUnitTest {
         for (String name : map.values()) {
             assertThat(name).isIn(map.values());
         }
+        assertThat(map.values()).containsExactlyInAnyOrder("Daniel", "Marko");
     }
 
 }