src/vs/workbench/api/common/extHostLanguageFeatures.ts/ExtHostLanguageFeatures/_addNewAdapter
class ExtHostLanguageFeatures:	private _addNewAdapter(adapter: Adapter, extension: IExtensionDescription): number {
		const handle = this._nextHandle();
		this._adapter.set(handle, new AdapterData(adapter, extension));
		return handle;
	}