src/vs/workbench/services/environment/browser/environmentService.ts/BrowserWorkbenchEnvironmentService/filesToMerge
class BrowserWorkbenchEnvironmentService:	get filesToMerge(): IPath[] | undefined {
		if (this.payload) {
			const fileToMerge1 = this.payload.get('mergeFile1');
			const fileToMerge2 = this.payload.get('mergeFile2');
			const fileToMergeBase = this.payload.get('mergeFileBase');
			const fileToMergeResult = this.payload.get('mergeFileResult');
			if (fileToMerge1 && fileToMerge2 && fileToMergeBase && fileToMergeResult) {
				return [
					{ fileUri: URI.parse(fileToMerge1) },
					{ fileUri: URI.parse(fileToMerge2) },
					{ fileUri: URI.parse(fileToMergeBase) },
					{ fileUri: URI.parse(fileToMergeResult) }
				];
			}
		}

		return undefined;
	}