src/vs/workbench/api/common/extHostExtensionService.ts/AbstractExtHostExtensionService/_startExtensionHost
class AbstractExtHostExtensionService:	private _startExtensionHost(): Promise<void> {
		if (this._started) {
			throw new Error(`Extension host is already started!`);
		}
		this._started = true;

		return this._readyToStartExtensionHost.wait()
			.then(() => this._readyToRunExtensions.open())
			.then(() => this._handleEagerExtensions())
			.then(() => {
				this._eagerExtensionsActivated.open();
				this._logService.info(`Eager extensions activated`);
			});
	}