property.kt

 fun tryItOut() {
  // Also since the block is the only parameter we can even drop the parenthesis all together!
    workbook {
        // We can directly set the value for isHidden!
        isHidden = true
        
        // We cannot change setSelectedTab because Workbook only has a setter for this and no getter (because POI is a PITA).
        // This prevents Kotlin from autogenerating the "synthetic accessor"
        setSelectedTab(2)
    }
}