diff --git a/sample/src/main/res/layout/activity_calls.xml b/sample/src/main/res/layout/activity_calls.xml
index e2f87a0..10e0e6c 100644
--- a/sample/src/main/res/layout/activity_calls.xml
+++ b/sample/src/main/res/layout/activity_calls.xml
@@ -4,6 +4,6 @@
     android:id="@+id/call_list"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    tools:context=".CallsActivity">
-
-</android.support.v7.widget.RecyclerView>
\ No newline at end of file
+    tools:context=".CallsActivity"
+    tools:listitem="@layout/item_call"
+    tools:itemCount="5"/>
\ No newline at end of file
diff --git a/sample/src/main/res/layout/activity_perform_call.xml b/sample/src/main/res/layout/activity_perform_call.xml
index 1a44ab0..58c16ae 100644
--- a/sample/src/main/res/layout/activity_perform_call.xml
+++ b/sample/src/main/res/layout/activity_perform_call.xml
@@ -11,8 +11,6 @@
         android:layout_width="match_parent"
         android:layout_height="0dp"
         android:layout_marginEnd="8dp"
-        android:layout_marginLeft="8dp"
-        android:layout_marginRight="8dp"
         android:layout_marginStart="8dp"
         android:layout_marginTop="8dp"
         app:layout_constraintBottom_toTopOf="@+id/container_param1"
@@ -32,8 +30,6 @@
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:layout_marginEnd="8dp"
-        android:layout_marginLeft="8dp"
-        android:layout_marginRight="8dp"
         android:layout_marginStart="8dp"
         app:layout_constraintBottom_toTopOf="@+id/container_param2"
         app:layout_constraintEnd_toEndOf="parent"
@@ -51,8 +47,6 @@
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:layout_marginEnd="8dp"
-        android:layout_marginLeft="8dp"
-        android:layout_marginRight="8dp"
         android:layout_marginStart="8dp"
         app:layout_constraintBottom_toTopOf="@+id/container_param3"
         app:layout_constraintEnd_toEndOf="parent"
@@ -69,8 +63,6 @@
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:layout_marginEnd="8dp"
-        android:layout_marginLeft="8dp"
-        android:layout_marginRight="8dp"
         android:layout_marginStart="8dp"
         app:layout_constraintBottom_toTopOf="@+id/container_param4"
         app:layout_constraintEnd_toEndOf="parent"
@@ -87,8 +79,6 @@
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:layout_marginEnd="8dp"
-        android:layout_marginLeft="8dp"
-        android:layout_marginRight="8dp"
         android:layout_marginStart="8dp"
         app:layout_constraintBottom_toTopOf="@+id/button_send"
         app:layout_constraintEnd_toEndOf="parent"
@@ -106,8 +96,6 @@
         android:layout_height="wrap_content"
         android:layout_marginBottom="8dp"
         android:layout_marginEnd="8dp"
-        android:layout_marginLeft="8dp"
-        android:layout_marginRight="8dp"
         android:layout_marginStart="8dp"
         android:text="@string/action_send"
         app:layout_constraintBottom_toBottomOf="parent"
diff --git a/sample/src/main/res/layout/activity_second.xml b/sample/src/main/res/layout/activity_second.xml
index 1965533..a75b38a 100644
--- a/sample/src/main/res/layout/activity_second.xml
+++ b/sample/src/main/res/layout/activity_second.xml
@@ -25,14 +25,14 @@
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:layout_weight="1"
-            android:textSize="11sp"
+            android:textSize="12sp"
             android:text="Subscribe"/>
         <Button
             android:id="@+id/unsubscribe"
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:layout_weight="1"
-            android:textSize="11sp"
+            android:textSize="12sp"
             android:text="Unsubscribe"/>
     </LinearLayout>
 </android.support.constraint.ConstraintLayout>
diff --git a/sample/src/main/res/layout/item_call.xml b/sample/src/main/res/layout/item_call.xml
index 3f13859..751a629 100644
--- a/sample/src/main/res/layout/item_call.xml
+++ b/sample/src/main/res/layout/item_call.xml
@@ -9,5 +9,6 @@
     android:padding="16dp"
     android:background="?attr/selectableItemBackground"
     android:clickable="true"
+    android:focusable="true"
     tools:text="Sample">
 </TextView>
\ No newline at end of file