* @param {Object/Number} pad (optional) Pad provides a way to specify "padding" of the constraints,
* and can be either a number for symmetrical padding (4 would be equal to `{left:4, right:4, top:4, bottom:4}`) or
* an object containing the sides to pad. For example: `{right:10, bottom:10}`
* @param {Object/Number} pad (optional) Pad provides a way to specify "padding" of the constraints,
* and can be either a number for symmetrical padding (4 would be equal to `{left:4, right:4, top:4, bottom:4}`) or
* an object containing the sides to pad. For example: `{right:10, bottom:10}`