src/vs/editor/common/languages/languageConfigurationRegistry.ts/ComposedLanguageConfiguration/register
class ComposedLanguageConfiguration:	public register(
		configuration: LanguageConfiguration,
		priority: number
	): IDisposable {
		const entry = new LanguageConfigurationContribution(
			configuration,
			priority,
			++this._order
		);
		this._entries.push(entry);
		this._resolved = null;
		return toDisposable(() => {
			for (let i = 0; i < this._entries.length; i++) {
				if (this._entries[i] === entry) {
					this._entries.splice(i, 1);
					this._resolved = null;
					break;
				}
			}
		});
	}