         }
     }
     
+    /**
+     Associates each Presentr type with a default transition type, in case one is not provided to the Presentr object.
+     
+     - returns: Return a 'TransitionType' which describes a system provided or custom transition animation.
+     */
     func defaultTransitionType() -> TransitionType{
         switch self {
         case .Alert, .Popup, .BottomHalf:

    case Full
    case Custom(size: Float)

    func calculateWidth(parentSize: CGSize) -> Float{
        switch self {
        case .Default:

}

/**
 Describes the presented presented view controller's center position. It is meant to be non-specific, but we can use the 'calculatePoint' method when we want to calculate the exact point by passing in the 'containerBounds' rect that only the presentation controller should be aware of.
 
 - Center:       Center of the screen.
 - TopCenter:    Center of the top half of the screen.
 - BottomCenter: Center of the bottom half of the screen.
 */
public enum ModalCenterPosition {
    
    case Center
    case TopCenter
    case BottomCenter
    
    /**
     Calculates the exact position for the presented view controller center.
     
     - parameter containerBounds: The container bounds the controller is being presented in.
     
     - returns: CGPoint representing the presented view controller's center point.
     */
    func calculatePoint(containerBounds: CGRect) -> CGPoint{
        switch self {
        case .Center:
