src/vs/workbench/api/common/extHostExtensionService.ts/AbstractExtHostExtensionService/$activate
class AbstractExtHostExtensionService:	public async $activate(extensionId: ExtensionIdentifier, reason: ExtensionActivationReason): Promise<boolean> {
		await this._readyToRunExtensions.wait();
		if (!this._myRegistry.getExtensionDescription(extensionId)) {
			// unknown extension => ignore
			return false;
		}
		await this._activateById(extensionId, reason);
		return true;
	}