.getNumberofPages() returns incorrect value

static int pageCount(byte[] document) { withDocument(document) { PDDocument pdf -> pdf.getNumberOfPages() } }


static Object withDocument(byte[] document, Closure clos) {
    PDDocument doc

    try {
        // Read the PDF file via PdfBox
        ByteArrayInputStream bais = new ByteArrayInputStream(document)
        doc = PDDocument.load(bais, MemoryUsageSetting.setupTempFileOnly())

        // Clone the Closure as a security measureee
        Closure clone = clos.clone()

        // Execute the custom processing on the PDDocument
        clone(doc)
    } finally {
        doc?.close()
    }
}