code: def create_line_plot(df):
      
      fig = Figure("/mg/line_plot/", "mg_line_plot")
      fig.graphics.transition_on_update(True)
      fig.graphics.animate_on_load()
      fig.layout.set_size(width=450, height=200)
      fig.layout.set_margin(left=40, right=40)
      return LineChart(df, fig, "Date", ["value"],
          init_params={"Data": "Steps"}, timeseries=True)
docs: create a mg line plot
  
          Args:
              df (pandas.DataFrame): data to plot