Create a good way to send Margin or Tooltip

[camilosampedro]

Types like Margin or Offset are interfaces in Typescript's NvD3 facade to allow codes like:

chart.margin({
    // With optional left or right for example
    top: 30,
    bottom: 30
})

One thing I have thought to implement is named parameters with default values:

def margin(left: Int = 0, right: Int = 0, up: Int = 0, bottom: Int = 0): this.type

The problem is that this methods are overloaded with a parameter-less method that returns the actual value of that property:

def margin/*()*/: Margin

Let's find a way to create an easy way to bind and implement this functionality, and at the end methods like margin receive this objects with optional values.