'Check that the arguments to config.get(...) are valid.'

def _check_config(self, node):

    try:
        sect_arg = utils.get_argument_from_call(node, position=0, keyword='sectname')
        opt_arg = utils.get_argument_from_call(node, position=1, keyword='optname')
    except utils.NoSuchArgumentError:
        return
    sect_arg = utils.safe_infer(sect_arg)
    opt_arg = utils.safe_infer(opt_arg)
    if (not (isinstance(sect_arg, astroid.Const) and isinstance(opt_arg, astroid.Const))):
        return
    try:
        configdata.DATA[sect_arg.value][opt_arg.value]
    except KeyError:
        self.add_message('bad-config-call', node=node, args=(sect_arg.value, opt_arg.value))
