How to use the @bentley/imodeljs-backend.IModelJsFs.existsSync function in @bentley/imodeljs-backend

export function createFilePath(filePath: string) {
  // ###TODO: Make this function platform independent
  const files = filePath.split(/\/|\\/); // /\.[^/.]+$/ // /\/[^\/]+$/
  let curFile = "";
  for (const file of files) {
    if (file === "") break;
    curFile += file + "\\";
    if (!IModelJsFs.existsSync(curFile)) IModelJsFs.mkdirSync(curFile);
  }
}

export function createNewCsvFile(filePath: string, fileName: string, data: Map): boolean {
  const file = path.join(filePath, fileName);
  if (!IModelJsFs.existsSync(filePath)) createFilePath(filePath);
  if (!IModelJsFs.existsSync(file)) {
    try {
      let colNames = "";
      data.forEach((_value, colName) => {
        colNames += colName + ",";
      });
      colNames += "\r\n";
      IModelJsFs.writeFileSync(file, colNames);
    } catch (err) {
      /* Handle the error */
    }
    return true;
  } else {
    return false;
  }
}

export function createNewCsvFile(filePath: string, fileName: string, data: Map): boolean {
  const file = path.join(filePath, fileName);
  if (!IModelJsFs.existsSync(filePath)) createFilePath(filePath);
  if (!IModelJsFs.existsSync(file)) {
    try {
      let colNames = "";
      data.forEach((_value, colName) => {
        colNames += colName + ",";
      });
      colNames += "\r\n";
      IModelJsFs.writeFileSync(file, colNames);
    } catch (err) {
      /* Handle the error */
    }
    return true;
  } else {
    return false;
  }
}

public async getDefaultConfigs(): Promise {
    let jsonStr = "";
    let defaultJsonFile;
    if (MobileRpcConfiguration.isMobileBackend && process.env.DOCS) {
      defaultJsonFile = path.join(process.env.DOCS, "MobilePerformanceConfig.json");
    } else {
      defaultJsonFile = "./src/backend/DefaultConfig.json";
    }
    if (IModelJsFs.existsSync(DisplayPerfRpcInterface.jsonFilePath)) {
      jsonStr = IModelJsFs.readFileSync(DisplayPerfRpcInterface.jsonFilePath).toString();
    } else if (IModelJsFs.existsSync(defaultJsonFile)) {
      jsonStr = IModelJsFs.readFileSync(defaultJsonFile).toString();
    }
    let argOutputPath: string | undefined;
    process.argv.forEach((arg, index) => {
      if (index >= 2 && arg !== "chrome" && arg !== "edge" && arg !== "firefox" && arg.split(".").pop() !== "json") {
        while (arg.endsWith("\\") || arg.endsWith("\/"))
          arg = arg.slice(0, -1);
        argOutputPath = "\"argOutputPath\": \"" + arg + "\",";
      }
    });

    if (argOutputPath) {
      const firstBraceIndex = jsonStr.indexOf("{") + 1;
      jsonStr = jsonStr.slice(0, firstBraceIndex) + argOutputPath + jsonStr.slice(firstBraceIndex);

public async savePng(fileName: string, png: string) {
    let filePath;
    if (MobileRpcConfiguration.isMobileBackend && process.env.DOCS) {
      filePath = process.env.DOCS;
      fileName = path.join(filePath, fileName);
    } else {
      filePath = this.getFilePath(fileName);
    }
    if (!IModelJsFs.existsSync(filePath)) createFilePath(filePath);
    if (IModelJsFs.existsSync(fileName)) IModelJsFs.unlinkSync(fileName);
    const buf = Buffer.from(png, "base64");
    IModelJsFs.writeFileSync(fileName, buf);
  }

public async readExternalSavedViews(bimfileName: string): Promise {
    const esvFileName = this.createEsvFilename(bimfileName);
    if (!IModelJsFs.existsSync(esvFileName)) {
      return "";
    }
    const jsonStr = IModelJsFs.readFileSync(esvFileName).toString();
    if (undefined === jsonStr)
      return "";
    return jsonStr;
  }

public async saveReport(): Promise {
    const pth = "./lib/outputdir";
    if (!IModelJsFs.existsSync(pth))
      IModelJsFs.mkdirSync(pth);
    const csvPath = path.join(pth, "IntegrationPefTests.csv");
    TestRpcImpl.reporter.exportCSV(csvPath);
  }

public async savePng(fileName: string, png: string) {
    let filePath;
    if (MobileRpcConfiguration.isMobileBackend && process.env.DOCS) {
      filePath = process.env.DOCS;
      fileName = path.join(filePath, fileName);
    } else {
      filePath = this.getFilePath(fileName);
    }
    if (!IModelJsFs.existsSync(filePath)) createFilePath(filePath);
    if (IModelJsFs.existsSync(fileName)) IModelJsFs.unlinkSync(fileName);
    const buf = Buffer.from(png, "base64");
    IModelJsFs.writeFileSync(fileName, buf);
  }

public async saveCsv(outputPath: string, outputName: string, rowDataJson: string, csvFormat?: string): Promise {
    const rowData = new Map(JSON.parse(rowDataJson)) as Map;
    const testName = rowData.get("Test Name") as string;
    rowData.delete("Test Name");
    if (csvFormat === "original") {
      rowData.delete("Browser");
      if (outputPath !== undefined && outputName !== undefined) {
        if (MobileRpcConfiguration.isMobileBackend && process.env.DOCS)
          outputPath = process.env.DOCS;
        let outputFile = this.createFullFilePath(outputPath, outputName);
        outputFile = outputFile ? outputFile : "";
        if (IModelJsFs.existsSync(outputFile)) {
          addColumnsToCsvFile(outputFile, rowData);
        } else {
          createNewCsvFile(outputPath, outputName, rowData);
        }
        addDataToCsvFile(outputFile, rowData);
      }
    } else {
      const rowObject = this.mapToObj(rowData);
      if (process.env.browser) {
        rowObject.browser = process.env.browser;
      }
      const totalTime = rowObject["Total Time"] as number;
      const fps = rowObject["Effective FPS"] as number;
      this._reporter.addEntry("DisplayTests", testName, "Total time", totalTime, rowObject);
      this._reporter.addEntry("DisplayTests", testName, "Effective FPS", fps, rowObject);
    }