'validate negative stock for entries current datetime onwards
will not consider cancelled entries'

def validate_negative_stock(self, sle):

    diff = (self.qty_after_transaction + flt(sle.actual_qty))
    if ((diff < 0) and (abs(diff) > 0.0001)):
        exc = sle.copy().update({u'diff': diff})
        self.exceptions.append(exc)
        return False
    else:
        return True
