    var sizeConstraint: ElementalSize { get }
    var isConfinedToMargins: Bool { get }
    var layoutDirection: ElementalLayoutDirection { get }
+   var cornerRadius: CGFloat { get }
 }
 
 public extension ElementalConfiguring {

   public var sizeConstraint: ElementalSize
   public var isConfinedToMargins: Bool
   public var layoutDirection: ElementalLayoutDirection
   
   public init(backgroundColor: UIColor = .clear, insets: UIEdgeInsets = .zero, isSelectable: Bool = true, width: CGFloat? = nil, height: CGFloat? = nil, sizeConstraint: ElementalSize = ElementalSize(), isConfinedToMargins: Bool = true, layoutDirection: ElementalLayoutDirection = .vertical) {
      self.backgroundColor = backgroundColor
      self.insets = insets
      self.isSelectable = isSelectable

   var sizeConstraint: ElementalSize { return ElementalSize() }
   var isConfinedToMargins: Bool { return true }
   var layoutDirection: ElementalLayoutDirection { return .vertical }
   var cornerRadius: CGFloat { return 0 }
}

open class ElementalConfiguration: ElementalConfiguring {
