Feature/kotlin list to map (#2216)

* Add project for hibernate immutable article
Add Event entity
Add hibernate configuration file
Add hibernateutil for configuration
Add test to match snippets from article

* Update master

* Add Kotlin test to convert list to map

kotlin/src/test/kotlin/com/baeldung/kotlin/ListToMapTest.kt

@@ -0,0 +1,35 @@
+package com.baeldung.kotlin
+
+import org.junit.Test
+import kotlin.test.assertTrue
+
+class ListToMapTest {
+
+    val user1 = User("John", 18, listOf("Hiking, Swimming"))
+    val user2 = User("Sara", 25, listOf("Chess, Board Games"))
+    val user3 = User("Dave", 34, listOf("Games, Racing sports"))
+
+    @Test
+    fun givenList_whenConvertToMap_thenResult() {
+        val myList = listOf(user1, user2, user3)
+        val myMap = myList.map { it.name to it.age }.toMap()
+
+        assertTrue(myMap.get("John") == 18)
+    }
+
+    @Test
+    fun givenList_whenAssociatedBy_thenResult() {
+        val myList = listOf(user1, user2, user3)
+        val myMap = myList.associateBy({ it.name }, { it.hobbies })
+
+        assertTrue(myMap.get("John")!!.contains("Hiking, Swimming"))
+    }
+
+    @Test
+    fun givenStringList_whenConvertToMap_thenResult() {
+        val myList = listOf("a", "b", "c")
+        val myMap = myList.map { it to it }.toMap()
+
+        assertTrue(myMap.get("a") == "a")
+    }
+}