def METHOD_NAME(self, guid: str, table: int):
    ptr = self.find(guid)
    append = ptr is None
    if append:
        ptr = self.baseptr + self.nitems * EFI_CONFIGURATION_TABLE.sizeof()
        append = True
    instance = EFI_CONFIGURATION_TABLE()
    instance.VendorGuid = utils.str_to_guid(guid)
    instance.VendorTable = table
    instance.saveTo(self.ql, ptr)
    if append:
        self.nitems += 1