```class Testview: View(){ override val root = m...

# tornadofx

[devanand]

class Testview: View(){
  override val root = migpane("debug") {
      add(label("Hello world"),"wrap")
   }
}

fun EventTarget.migpane(lCc: String?="",op: (MigPane.() -> Unit)? = null) = opcr(this,MigPane(lCc), op)

results in error

Caused by: java.lang.IllegalArgumentException: Children: duplicate children added: parent = MigPane@1586794c
	at javafx.scene.Parent$2.onProposedChange(Parent.java:454)
	at com.sun.javafx.collections.VetoableListDecorator.add(VetoableListDecorator.java:206)
	at org.tbee.javafx.scene.layout.MigPane.add(Unknown Source)
	at org.tbee.javafx.scene.layout.MigPane.add(Unknown Source)
	at com.e8om.books.views.subViews.MainMenuView$root$1.invoke(MainMenuView.kt:10)
	at com.e8om.books.views.subViews.MainMenuView$root$1.invoke(MainMenuView.kt:8)
	at tornadofx.FXKt.opcr(FX.kt:436)
	at com.e8om.books.layouts.MigLayoutKt.migpane(MigLayout.kt:7)
	at com.e8om.books.layouts.MigLayoutKt.migpane$default(MigLayout.kt:7)
	at com.e8om.books.views.subViews.MainMenuView.<init>(MainMenuView.kt:9)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)