def update_by_config(self, config_dict):
        """ Update policies set by the config dictionary.

        Expect the policy_enabling_map structure to be (represented by YAML):
            - PolicyFoo:
              enabled: True
            - PolicyBar:
              enabled: False
              additional_field: 'is_ok'
        """
        policy_enabling_map = self._get_enabling_map(config_dict)
        self.enabled_policies = []

        for policy_name, is_policy_enabled in policy_enabling_map.items():
            if not self._is_policy_exists(policy_name):
                self._warn_unexistent_policy(policy_name)
                continue

            if is_policy_enabled:
                enabled_policy = self._get_policy(policy_name)
                self.enabled_policies.append(enabled_policy)
Update policies set by the config dictionary.

        Expect the policy_enabling_map structure to be (represented by YAML):
            - PolicyFoo:
              enabled: True
            - PolicyBar:
              enabled: False
              additional_field: 'is_ok'