diff --git a/Usability/Data Classes/Exercise 1/src/Task.kt b/Usability/Data Classes/Exercise 1/src/Task.kt
index f5138e7d..e47ec1e2 100644
--- a/Usability/Data Classes/Exercise 1/src/Task.kt	
+++ b/Usability/Data Classes/Exercise 1/src/Task.kt	
@@ -9,9 +9,11 @@ data class AirlineTicket(
 )
 
 fun main() {
+/*
   val ticket = AirlineTicket("Bruce", "Eckel", 123456, "DEN", "HND")
   println(ticket)
+*/
 }
 /* Expected output:
-AirlineTicket(first=Bruce, last=Eckel, ticket=123456, origin=DEN, destination=HND)
+AirlineTicket(firstName=Bruce, lastName=Eckel, ticket=123456, origin=DEN, destination=HND)
 */
\ No newline at end of file
diff --git a/Usability/Data Classes/Exercise 1/task-info.yaml b/Usability/Data Classes/Exercise 1/task-info.yaml
index 7ad1b827..4f56ce5e 100644
--- a/Usability/Data Classes/Exercise 1/task-info.yaml	
+++ b/Usability/Data Classes/Exercise 1/task-info.yaml	
@@ -2,5 +2,9 @@ type: edu
 files:
 - name: src/Task.kt
   visible: true
+  placeholders:
+  - offset: 30
+    length: 143
+    placeholder_text: // Implement AirlineTicket class
 - name: test/Tests.kt
   visible: false
diff --git a/Usability/Data Classes/Exercise 1/test/Tests.kt b/Usability/Data Classes/Exercise 1/test/Tests.kt
index 8fa59590..f0639f55 100644
--- a/Usability/Data Classes/Exercise 1/test/Tests.kt	
+++ b/Usability/Data Classes/Exercise 1/test/Tests.kt	
@@ -1,10 +1,30 @@
 package dataClassesExercise1
 
+import org.junit.Assert
 import org.junit.Test
 import util.TIMEOUT
-import util.untestable
+import util.checkParametersOfConstructor
+import util.loadClass
+import util.runAndCheckSystemOutput
 
 class TestDataClassesExercise1 {
   @Test(timeout = TIMEOUT)
-  fun test() = untestable()
+  fun test() {
+    val ticketClass = loadClass("dataClassesExercise1", "AirlineTicket")
+
+    val constructor = ticketClass.constructors.first()
+    checkParametersOfConstructor(constructor, ticketClass, listOf(
+      "firstName" to "kotlin.String",
+      "lastName" to "kotlin.String",
+      "ticket" to "kotlin.Int",
+      "origin" to "kotlin.String",
+      "destination" to "kotlin.String"
+    ))
+    Assert.assertTrue("'AirlineTicket' class is expected to be defined as 'data' class", ticketClass.isData)
+    runAndCheckSystemOutput("Wrong output",
+      "AirlineTicket(firstName=Bruce, lastName=Eckel, ticket=123456, origin=DEN, destination=HND)") {
+      val ticket = constructor.call("Bruce", "Eckel", 123456, "DEN", "HND")
+      println(ticket)
+    }
+  }
 }
\ No newline at end of file
diff --git a/Usability/Data Classes/Exercise 2/src/Task.kt b/Usability/Data Classes/Exercise 2/src/Task.kt
index ad5d7965..b28c0bbf 100644
--- a/Usability/Data Classes/Exercise 2/src/Task.kt	
+++ b/Usability/Data Classes/Exercise 2/src/Task.kt	
@@ -19,6 +19,6 @@ fun main() {
   val ticket = AirlineTicket("Bruce", "Eckel", 123456, "DEN", "HND")
   println(ticket.transferTicket("Svetlana", "Isakova"))
 }
-/* Expected output:
-AirlineTicket(first=Svetlana, last=Isakova, ticket=123456, origin=DEN, destination=HND)
+/* Output:
+AirlineTicket(firstName=Svetlana, lastName=Isakova, ticket=123456, origin=DEN, destination=HND)
 */
\ No newline at end of file
diff --git a/Usability/Data Classes/Exercise 2/task-info.yaml b/Usability/Data Classes/Exercise 2/task-info.yaml
index 7ad1b827..a100f10d 100644
--- a/Usability/Data Classes/Exercise 2/task-info.yaml	
+++ b/Usability/Data Classes/Exercise 2/task-info.yaml	
@@ -2,5 +2,9 @@ type: edu
 files:
 - name: src/Task.kt
   visible: true
+  placeholders:
+  - offset: 280
+    length: 70
+    placeholder_text: TODO()
 - name: test/Tests.kt
   visible: false
diff --git a/Usability/Data Classes/Exercise 2/test/Tests.kt b/Usability/Data Classes/Exercise 2/test/Tests.kt
index a6c6f225..e759728c 100644
--- a/Usability/Data Classes/Exercise 2/test/Tests.kt	
+++ b/Usability/Data Classes/Exercise 2/test/Tests.kt	
@@ -4,8 +4,11 @@ import org.junit.Assert
 import org.junit.Test
 
 class TestDataClassesExercise2 {
-    @Test fun testSolution() {
-        //TODO: implement your test here
-        Assert.assertTrue("Tests not implemented for the task", false)
-    }
+  @Test
+  fun testTransferTicket() {
+    val ticket = AirlineTicket("Bruce", "Eckel", 123456, "DEN", "HND")
+    Assert.assertEquals("Wrong result after copy",
+      AirlineTicket("Svetlana", "Isakova", 123456, "DEN", "HND"),
+      ticket.transferTicket("Svetlana", "Isakova"))
+  }
 }
\ No newline at end of file