'Render the table footer
@param table: the TABLE instance'

def xls_table_footer(self, rows):

    data = self.data
    columns = data.get('c')
    totals = data.get('t')
    if (not totals):
        return
    row = {}
    if columns:
        label = None
        span = 0
        for column in columns:
            has_value = (column in totals)
            if (label is None):
                if (not has_value):
                    span += 1
                    continue
                else:
                    label = self.totals_label
            row[column] = (totals[column] if has_value else '')
    row['_group'] = {'label': label, 'span': span, 'totals': True}
    row['_style'] = 'totals'
    rows.append(row)
