如何在dash下拉组件中添加全选选项？

pip install dash dash-core-components

import dash
import dash_core_components as dcc
import dash_html_components as html
from dash.dependencies import Input, Output

app = dash.Dash(__name__)

app.layout = html.Div([
    dcc.Dropdown(
        id='dropdown',
        options=[
            {'label': 'Option 1', 'value': 'option1'},
            {'label': 'Option 2', 'value': 'option2'},
            {'label': 'Option 3', 'value': 'option3'}
        ],
        multi=True
    ),
    html.Br(),
    dcc.Checkbox(
        id='select-all',
        label='Select All'
    ),
    html.Br(),
    html.Div(id='output')
])

@app.callback(
    Output('dropdown', 'value'),
    [Input('select-all', 'checked')]
)
def update_dropdown(checked):
    if checked:
        return [option['value'] for option in dropdown_options]
    else:
        return []

if __name__ == '__main__':
    app.run_server(debug=True)