src/vs/workbench/services/extensions/common/abstractExtensionService.ts/AbstractExtensionService/_getExtensionKind
class AbstractExtensionService:	private _getExtensionKind(extensionDescription: IExtensionDescription): ExtensionKind[] {
		if (extensionDescription.isUnderDevelopment && this._environmentService.extensionDevelopmentKind) {
			return this._environmentService.extensionDevelopmentKind;
		}

		return this._extensionManifestPropertiesService.getExtensionKind(extensionDescription);
	}