如何使用嵌套类别在bokeh中绘制堆叠的vbar

from bokeh.io import output_file, show
from bokeh.models import ColumnDataSource
from bokeh.plotting import figure

data = {
    'categories': ['A', 'B', 'C', 'D'],  # 类别
    'subcategories': ['X', 'Y', 'Z'],  # 子类别
    'values': [[1, 2, 3], [4, 5, 6], [7, 8, 9], [10, 11, 12]]  # 值
}
source = ColumnDataSource(data=data)

p = figure(x_range=data['categories'], plot_height=250, title='Stacked vbar')
p.vbar_stack(data['subcategories'], x='categories', width=0.9, color=['red', 'green', 'blue'], source=source)

p.y_range.start = 0  # 设置y轴起始值为0
p.xgrid.grid_line_color = None  # 隐藏x轴网格线
p.legend.location = 'top_left'  # 设置图例位置
p.legend.title = 'Subcategories'  # 设置图例标题
p.xaxis.axis_label = 'Categories'  # 设置x轴标签
p.yaxis.axis_label = 'Values'  # 设置y轴标签

output_file('stacked_vbar.html')  # 输出到HTML文件
show(p)  # 展示图