def METHOD_NAME(self):
    for att in self:
        att.xml_supplier_id = False
        att.invoices_number = False
        att.invoices_total = False
        att.invoices_date = False
        att.is_self_invoice = False
        if not att.ir_attachment_id.datas:
            continue
        wiz_obj = self.env["wizard.import.fatturapa"].with_context(
            from_attachment=att
        )
        fatt = wiz_obj.get_invoice_obj(att)
        cedentePrestatore = fatt.FatturaElettronicaHeader.CedentePrestatore
        partner_id = wiz_obj.getCedPrest(cedentePrestatore)
        att.xml_supplier_id = partner_id
        att.invoices_number = len(fatt.FatturaElettronicaBody)
        att.invoices_total = 0
        invoices_date = []
        for invoice_body in fatt.FatturaElettronicaBody:
            dgd = invoice_body.DatiGenerali.DatiGeneraliDocumento
            att.invoices_total += float(dgd.ImportoTotaleDocumento or 0)
            invoice_date = format_date(
                att.with_context(lang=att.env.user.lang).env,
                fields.Date.from_string(dgd.Data),
            )
            if invoice_date not in invoices_date:
                invoices_date.append(invoice_date)
            if dgd.TipoDocumento in SELF_INVOICE_TYPES:
                att.is_self_invoice = True
        att.invoices_date = " ".join(invoices_date)
        inconsistencies = wiz_obj.env.context.get("inconsistencies", False)
        att.inconsistencies = inconsistencies