Bokeh CheckBoxGroupButton

I m building a chart using bokeh. In this chart I m inserting a CheckBoxButtonGroup. I m using this code:

 LABELS = [" Produzione " + postazione + " " + stazione + " ",
              " Cycle time " + postazione + " " + stazione+ " ",
              " Scarti " + postazione + " " + stazione+ " ",
              " Avarie " + postazione + " " + stazione2+ " ",
              " Stati " + postazione + " "]
 checkbox_button_group = CheckboxButtonGroup(labels=LABELS, active=[0,0,0,0,0])

With this code, I thinked to display the 5 checkbox buttons no flagged. But if I try to render the page I can see this situation:

As you can see the first option is every time selected. It is possible to display at first time all option no selected?