diff --git a/.space.kts b/.space.kts
deleted file mode 100644
index 45b2ed53..00000000
--- a/.space.kts
+++ /dev/null
@@ -1,4 +0,0 @@
-job("Build") {
-    gradlew("openjdk:11", "build")
-}
-
diff --git a/demo/playground/src/jvmMain/kotlin/controlVision.kt b/demo/playground/src/jvmMain/kotlin/controlVision.kt
index f7a9c753..5cd1c2d2 100644
--- a/demo/playground/src/jvmMain/kotlin/controlVision.kt
+++ b/demo/playground/src/jvmMain/kotlin/controlVision.kt
@@ -1,9 +1,14 @@
 package space.kscience.visionforge.examples
 
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.isActive
+import kotlinx.coroutines.launch
+import kotlinx.html.h2
 import kotlinx.html.p
 import space.kscience.visionforge.VisionControlEvent
 import space.kscience.visionforge.html.*
 import space.kscience.visionforge.onClick
+import kotlin.time.Duration.Companion.seconds
 
 
 fun main() = serve {
@@ -25,6 +30,7 @@ fun main() = serve {
             }
         }
     }
+    h2 { +"Control elements" }
 
     vision {
         htmlCheckBox {
@@ -41,13 +47,19 @@ fun main() = serve {
             onValueChange(context) {
                 pushEvent(this)
             }
+            context.launch {
+                while (isActive) {
+                    delay(1.seconds)
+                    numberValue = ((numberValue?.toInt() ?: 0) + 1) % 10
+                }
+            }
         }
     }
 
 
     vision {
-        button("Click me"){
-            onClick(context){
+        button("Click me") {
+            onClick(context) {
                 pushEvent(this)
             }
         }
diff --git a/visionforge-core/src/commonMain/kotlin/space/kscience/visionforge/html/VisionOfHtml.kt b/visionforge-core/src/commonMain/kotlin/space/kscience/visionforge/html/VisionOfHtml.kt
index 2bd7b9de..b496cf07 100644
--- a/visionforge-core/src/commonMain/kotlin/space/kscience/visionforge/html/VisionOfHtml.kt
+++ b/visionforge-core/src/commonMain/kotlin/space/kscience/visionforge/html/VisionOfHtml.kt
@@ -18,7 +18,7 @@ import space.kscience.visionforge.*
 @Serializable
 public abstract class VisionOfHtml : AbstractVision() {
     public var classes: Set<String>
-        get() = properties.get(::classes.name,false).stringList?.toSet() ?: emptySet()
+        get() = properties[::classes.name, false].stringList?.toSet() ?: emptySet()
         set(value) {
             properties[::classes.name] = value.map { it.asValue() }
         }