Error when loading the PDF in a deno notebook

Short Course Q&A Build LLM Apps with LangChain.js
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I run the following code for loading a PDF in a deno notebook:

import { RecursiveCharacterTextSplitter } from "https://esm.sh/langchain@0.1.4/text_splitter";
import { PDFLoader } from "https://esm.sh/langchain@0.1.4/document_loaders/fs/pdf";
import * as parse from 'npm:pdf-parse/lib/pdf-parse.js'

const loader = new PDFLoader("hugo-test.pdf");
const rawCS229Docs = await loader.load();

And I got the following error:

Stack trace:
Error: No PDFJS.workerSrc specified
    at S (https://esm.sh/v135/pdf-parse@1.1.1/denonext/lib/pdf.js/v1.10.100/build/pdf.js:25:45754)
    at Y._initialize (https://esm.sh/v135/pdf-parse@1.1.1/denonext/lib/pdf.js/v1.10.100/build/pdf.js:25:46922)
    at new Y (https://esm.sh/v135/pdf-parse@1.1.1/denonext/lib/pdf.js/v1.10.100/build/pdf.js:25:46462)
    at t (https://esm.sh/v135/pdf-parse@1.1.1/denonext/lib/pdf.js/v1.10.100/build/pdf.js:25:35206)
    at z.parse (https://esm.sh/v135/langchain@0.1.4/denonext/document_loaders/fs/pdf.js:203:535)
    at async <anonymous>:2:22

Does someone know how to solve this?