An S4 class that represents estimated mean cumulative function (MCF) from
Models. The function `mcf`

produces objects of this class.

## Slots

`call`

Function call.

`formula`

Formula.

`spline`

A character.

`knots`

A numeric vector.

`degree`

A nonnegative integer.

`Boundary.knots`

A numeric vector.

`newdata`

A numeric matrix.

`MCF`

A data frame.

`level`

A numeric value between 0 and 1.

`na.action`

A length-one character vector.

`control`

A list.

`multiGroup`

A logical value.