src/vs/workbench/services/experiment/common/experimentService.ts/ExperimentServiceFilterProvider/getFilterValue
class ExperimentServiceFilterProvider:	getFilterValue(filter: string): string | null {
		switch (filter) {
			case Filters.ApplicationVersion:
				return this.version; // productService.version
			case Filters.Build:
				return this.appName; // productService.nameLong
			case Filters.ClientId:
				return this.machineId;
			case Filters.Language:
				return platform.language;
			case Filters.ExtensionName:
				return 'vscode-core'; // always return vscode-core for exp service
			case Filters.TargetPopulation:
				return this.targetPopulation;
			default:
				return '';
		}
	}