def expand_chart_data(chart, offset_down=1, offset_up=0, allow_cb=_true):
with xlcom.pause_screen_updating(chart.Application):
for series in chart.SeriesCollection():
if allow_cb(series):
expand_series(series, offset_down, offset_up)
def expand_series(series, offset_down, offset_up=0):
with xlcom.pause_screen_updating(series.Application):
old_formula = series.Formula
full_form = _expand_formula(old_formula, offset_down, offset_up)
series.Formula = full_form
