GtkButton\" id=\"button1\"&gt;\n        &lt;property name=\"label\" translatable=\"yes\"&gt;Hello&lt;/property&gt;\n        &lt;property name=\"visible\"&gt;True&lt;/property&gt;\n        &lt;property name=\"can_focus\"&gt;True&lt;/property&gt;\n        &lt;property name=\"receives_default\"&gt;True&lt;/property&gt;\n        &lt;signal name=\"clicked\" handler=\"on_button1_clicked\"/&gt;\n      &lt;/object&gt;\n    &lt;/child&gt;\n  &lt;/object&gt;\n&lt;/interface&gt;\n"
    val mainWindow = GtkBuilder.get