Well I'm working on jasper report and I want to create a new balance sheet report, so I reviewed that the following file: "addons\account\report\account_financial_report.py" returns a list with a dictionary with all information needed for balance sheet, I did some changes in that file to parse it to new report, but I want to create a new module and inherit that method (get_lines) to do my changes in my own files and don't use the openerp files. Is there some way to access to that method and get that list ?

I tried with the following:

class new_report_balance_sheet(osv.Model):

    _name = 'accounting.report'
    _inherit = 'accounting.report'
        

    def start_report(self, cr, uid, ids, data, context=None):
        my_val=self.pool.get('account.financial.report.report.account.common')