Incorrect 'plot_background' area (with empty space capture)

[OLarionova-HORIS]

from lets_plot import *
LetsPlot.setup_html()

import numpy as np
np.random.seed(42)

data = {'x': np.random.randint(10, size=50)}

ggplot(data, aes(x='x')) + \
    geom_bar() + \
    coord_fixed(0.5) + \
    theme(plot_background=element_rect(size=2, fill='light_grey'))

The filled area corresponds to the overall size of the plot:

It's more correct not to take the empty space around - use the plotting area with all titles and margins. The expected result will be like this: