如何在swift macOS中旋转PDF中的页面？

import CoreGraphics

guard let pdfURL = Bundle.main.url(forResource: "example", withExtension: "pdf") else {
    print("PDF file not found.")
    return
}

guard let pdfDocument = CGPDFDocument(pdfURL as CFURL) else {
    print("Failed to load PDF document.")
    return
}

let pageCount = pdfDocument.numberOfPages

for pageNumber in 1...pageCount {
    guard let page = pdfDocument.page(at: pageNumber) else {
        print("Failed to load page \(pageNumber).")
        continue
    }
    
    // 在这里进行页面旋转操作
}

let pageRect = page.getBoxRect(.mediaBox)
let rotationAngle = CGFloat.pi / 2 // 顺时针旋转90度

let rotatedPageRect = CGRect(x: 0, y: 0, width: pageRect.height, height: pageRect.width)
let rotatedPageTransform = CGAffineTransform(rotationAngle: rotationAngle)

let rotatedPageContext = CGContext(
    data: nil,
    width: Int(rotatedPageRect.width),
    height: Int(rotatedPageRect.height),
    bitsPerComponent: page.bitsPerComponent,
    bytesPerRow: 0,
    space: page.colorSpace ?? CGColorSpaceCreateDeviceRGB(),
    bitmapInfo: page.bitmapInfo.rawValue
)

rotatedPageContext?.concatenate(rotatedPageTransform)
rotatedPageContext?.drawPDFPage(page)

let rotatedPage = rotatedPageContext?.makePDFPage()

let outputURL = URL(fileURLWithPath: "/path/to/output.pdf")
let outputDocument = CGPDFDocument(outputURL as CFURL)

let outputContext = CGContext(
    data: nil,
    width: Int(pageRect.width),
    height: Int(pageRect.height),
    bitsPerComponent: 8,
    bytesPerRow: 0,
    space: CGColorSpaceCreateDeviceRGB(),
    bitmapInfo: CGImageAlphaInfo.noneSkipLast.rawValue
)

outputContext?.beginPDFPage(nil)
outputContext?.draw(rotatedPage!, in: pageRect)
outputContext?.endPDFPage()

outputContext?.closePDF()

let outputData = NSMutableData()
let outputConsumer = CGDataConsumer(data: outputData as CFMutableData)
let outputPDF = outputContext?.createPDFRepresentation(of: CGRect(x: 0, y: 0, width: pageRect.width, height: pageRect.height), withOptions: nil)

outputPDF?.write(to: outputConsumer!, options: [:])

outputData.write(to: outputURL, atomically: true)