如何在PdfTron/ Pdf.js (React App)中使用loadDocument()函数加载一个给出文件夹内路径的文档

import { PDFTronWebViewer } from 'pdftron-webviewer';
import pdfjs from 'pdfjs-dist';

class PDFViewer extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      documentPath: '/path/to/document.pdf'
    };
  }
  ...
}

render() {
  return (
    <div>
      <PDFTronWebViewer
        document={this.state.documentPath}
        ...
      />
    </div>
  );
}

render() {
  return (
    <div>
      <canvas id="pdf-canvas"></canvas>
    </div>
  );
}

componentDidMount() {
  const canvas = document.getElementById('pdf-canvas');
  const context = canvas.getContext('2d');

  pdfjs.getDocument(this.state.documentPath)
    .promise.then((pdf) => {
      pdf.getPage(1).then((page) => {
        const viewport = page.getViewport({ scale: 1 });
        canvas.width = viewport.width;
        canvas.height = viewport.height;

        page.render({
          canvasContext: context,
          viewport: viewport
        });
      });
    });
}