Parameters: 
 vpstats : list of dicts
A list of dictionaries containing stats for each violin plot.
Required keys are:
coords : A list of scalars containing the coordinates that
the violin's kernel density estimate were evaluated at.
vals : A list of scalars containing the values of the
kernel density estimate at each of the coordinates given
in coords.
mean : The mean value for this violin's dataset.
median : The median value for this violin's dataset.
min : The minimum value for this violin's dataset.
max : The maximum value for this violin's dataset.
 positions : arraylike, default = [1, 2, ..., n]
Sets the positions of the violins. The ticks and limits are
automatically set to match the positions.
 vert : bool, default = True.
If true, plots the violins vertically.
Otherwise, plots the violins horizontally.
 widths : arraylike, default = 0.5
Either a scalar or a vector that sets the maximal width of
each violin. The default is 0.5, which uses about half of the
available horizontal space.
 showmeans : bool, default = False
If true, will toggle rendering of the means.
 showextrema : bool, default = True
If true, will toggle rendering of the extrema.
 showmedians : bool, default = False
If true, will toggle rendering of the medians.
