src/vs/platform/configuration/common/configurationModels.ts/Configuration/compareAndUpdateLocalUserConfiguration
class Configuration:	compareAndUpdateLocalUserConfiguration(user: ConfigurationModel): IConfigurationChange {
		const { added, updated, removed, overrides } = compare(this.localUserConfiguration, user);
		const keys = [...added, ...updated, ...removed];
		if (keys.length) {
			this.updateLocalUserConfiguration(user);
		}
		return { keys, overrides };
	}