PDFをJPGにマージするNode API

import * as fs from "fs";

const wordsApi = new WordsApi("####-####-####-####-####", "##################");

const document = fs.createReadStream("Input1.pdf");
const mergeProps = new model.DocumentEntry({
    fileReference: model.FileReference.fromRemoteFilePath("Input2.pdf"),
    importFormatMode: "KeepSourceFormatting"
})
const documentEntries = [
    mergeProps
]
const documentList = new model.DocumentEntryList({
    documentEntries: documentEntries
})
const appendDocumentOnline = new model.AppendDocumentOnlineRequest({
    document: document,
    documentList: documentList
});

wordsApi.appendDocumentOnline(appendDocumentOnline)
.then((appendDocumentOnlineResult) => {    
    console.log("Result of AppendDocumentOnline: ", appendDocumentOnlineResult);

    const splitDocumentOnline = new model.SplitDocumentOnlineRequest({
        document: appendDocumentOnlineResult,
        format: "jpg",
        zipOutput: true
    });

    wordsApi.splitDocumentOnline(splitDocumentOnline)
    .then((splitDocumentOnlineResult) => {        
        console.log("Result of SplitDocumentOnline: ", splitDocumentOnlineResult);
    });
});