x::AbstractVector
y::AbstractVector
group::AbstractVector
stacked::Bool = false
normalize::Bool = false

using Vega, KernelDensity, Distributions

x = rand(Beta(3.0, 2.0), 10)
k = kde(x)

areaplot(x = k.x, y = k.density)

using Vega

x = [0,1,2,3,4,5,6,7,8,9,0,1,2,3,4,5,6,7,8,9]
y = [28, 43, 81, 19, 52, 24, 87, 17, 68, 49, 55, 91, 53, 87, 48, 49, 66, 27, 16, 15]
g = [0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1]

a = areaplot(x = x, y = y, group = g, stacked = true)

a = areaplot(x = x, y = y, group = g, stacked = true, normalize = true)
colorscheme!(a, palette = ("Reds", 4))
hover!(a, opacity = 0.75)
hline!(a, value = 0.5, strokeDash = 5)