src/vs/workbench/api/node/extHostExtensionService.ts/NodeModuleRequireInterceptor/_installInterceptor
class NodeModuleRequireInterceptor:	protected _installInterceptor(): void {
		const that = this;
		const node_module = <any>require.__$__nodeRequire('module');
		const original = node_module._load;
		node_module._load = function load(request: string, parent: { filename: string; }, isMain: boolean) {
			for (let alternativeModuleName of that._alternatives) {
				let alternative = alternativeModuleName(request);
				if (alternative) {
					request = alternative;
					break;
				}
			}
			if (!that._factories.has(request)) {
				return original.apply(this, arguments);
			}
			return that._factories.get(request)!.load(
				request,
				URI.file(realpathSync(parent.filename)),
				request => original.apply(this, [request, parent, isMain])
			);
		};
	}