validate_config

        High-level api: Validate config against models. ConfigError is raised
        if the config has issues.

        Returns
        -------

        None
            There is no return of this method.

        Raises
        ------

        ConfigError
            If config contains error.

def validate_config(self):
        '''validate_config

        High-level api: Validate config against models. ConfigError is raised
        if the config has issues.

        Returns
        -------

        None
            There is no return of this method.

        Raises
        ------

        ConfigError
            If config contains error.
        '''

        self.roots
        for child in self.ele.getchildren():
            self._validate_node(child)