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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _load_config(self):
 """ Loads the configuration from YAML, if no override config was passed in initially. """


        if (
            self.config
        ):  # any config being pre-set at init will short circuit out, but not a plain {}
            return

        # Verify that we're in a project
        repo_root = self.repo_root
        if not repo_root:
            raise NotInProject(
                "No git repository was found in the current path. You must be in a git repository to set up and use CCI for a project."
            )

        # Verify that the project's root has a config file
        if not self.config_project_path:
            raise ProjectConfigNotFound(
                "The file {} was not found in the repo root: {}. Are you in a CumulusCI Project directory?".format(
                    self.config_filename, repo_root
                )
            )

        # Load the project's yaml config file
        with open(self.config_project_path, "r") as f_config:
            project_config = ordered_yaml_load(f_config)

        if project_config:
            self.config_project.update(project_config)

        # Load the local project yaml config file if it exists
        if self.config_project_local_path:
            with open(self.config_project_local_path, "r") as f_local_config:
                local_config = ordered_yaml_load(f_local_config)
            if local_config:
                self.config_project_local.update(local_config)

        # merge in any additional yaml that was passed along
        if self.additional_yaml:
            additional_yaml_config = ordered_yaml_load(self.additional_yaml)
            if additional_yaml_config:
                self.config_additional_yaml.update(additional_yaml_config)

        self.config = merge_config(
            OrderedDict(
                [
                    ("global_config", self.config_global),
                    ("global_local", self.config_global_local),
                    ("project_config", self.config_project),
                    ("project_local_config", self.config_project_local),
                    ("additional_yaml", self.config_additional_yaml),
                ]
            )
        )