code: def slider_update(attrname, old, new):
      year = slider.value
      label.text = str(year)
      source.data = data[year]
  
file_path: bokeh/examples/server/app/gapminder/main.py
imports: import pandas
  from bokeh.io import curdoc
  from bokeh.layouts import layout
  from bokeh.models import Button, CategoricalColorMapper, ColumnDataSource, HoverTool, Label, SingleIntervalTicker, Slider
  from bokeh.palettes import Spectral6
  from bokeh.plotting import figure
  from .data import process_data
label_desc: Use image node_id 2 for calling a global function with example usage: slider_update(attrname, old, new) without return types