Macro impl_into_plot 

macro_rules! impl_into_plot {
    (impl<$($generic:ident),*> $ty:ty $(where $($bound:tt)*)?) => { ... };
}

Make a Plot usable as a child element.

impl_into_plot!(impl<T> MyPlot<T> where T: 'static);
impl_into_plot!(impl<> Sparkline);