async function getDocument() {
    // Initialize request argument(s)
    const documentRequest = {
      // The full resource name of the document, e.g.:
      // projects/{project_number}/locations/{location}/documents/{document_id}
      name: serviceClient.projectLocationDocumentPath(
        projectNumber,
        location,
        documentId
      ),
      requestMetadata: {userInfo: {id: userId}},
    };

    // Make Request
    const response = serviceClient.getDocument(documentRequest);

    // Print out response
    response.then(
      result => console.log(`Document Found: ${JSON.stringify(result)}`),
      error => console.log(`${error}`)
    );
  }
TODO(developer): Uncomment these variables before running the sample.
const projectNumber = 'YOUR_PROJECT_NUMBER';
const location = 'YOUR_PROJECT_LOCATION'; // Format is 'us' or 'eu'
documentId = 'YOUR_DOCUMENT_ID';
const userId = 'user:xxx@example.com'; // Format is "user:xxx@example.com"