geom_boxplot() doesn't apply alpha to outliers

[IKupriyanov-HORIS]

import numpy as np
from lets_plot import *
LetsPlot.setup_html()
n = 100
np.random.seed(42)
x = np.random.choice(['a', 'b', 'c'], size=n)
y = np.random.normal(size=n)
ggplot({'x': x, 'y': y}, aes(x='x', y='y')) + \
    geom_boxplot(alpha=0.2)

[alshan]

My guess, on boxplot (as well as on barchart, area, polygons etc.) alpha is only applied to "fill".

[IKupriyanov-HORIS]

ggplot2 also applies alpha to outliers:

[alshan]

Outliers appearance is also controlled by additional parameters outlier_[color,fill,shape,size].
In this vein, we could add two more parameters: outlier_alpha, outlier_stroke.