efine the Circle Class $(2$ marks$)$ Define a class named Circle. The class should have one private attribute: radius $($default to $1\mathrm{.}0).$ Include the following methods:init $($self$,$ radius: float$)-$ Constructor to initialize the ra$-$ dius.get radius$($self$)->$ float $-$ Returns the radius.set radius$($self$,$ radius: float$)-$ Sets a new radius $($shouldvalidate that the radius is positive$).$calculate area$($self$)->$ float $-$ Returns the area of the circle$(\backslash$times radius$2).$calculate circumference$($self$)->$ float $-$ Returns the circum$-$ference of the circle $(2\backslash$times $\backslash$times radius$).$