title: Google Sheets API returns "Invalid values[3][1]: struct_value {\n}\n" error
body: <p>I'm using the <a href="https://developers.google.com/resources/api-libraries/documentation/sheets/v4/java/latest/overview-summary.html" rel="nofollow noreferrer">Google Sheets API v4 for Java</a> to fill a spreadsheet with some values:</p>
  
  <pre><code>String spreadsheetID = ...;
  Spreadsheets service = new Sheets.Builder(GoogleNetHttpTransport.newTrustedTransport(),
      JacksonFactory.getDefaultInstance(), credential).setApplicationName("Test").build().spreadsheets();
  
  List&lt;List&lt;Object&gt;&gt; content = new ArrayList&lt;&gt;();
  content.add(Arrays.asList("Client", "John Doe"));
  content.add(Arrays.asList("Date", new Date()));
  service.values().update(spreadsheetID, "Sheet1!C3:D4",
      new ValueRange().setValues(content)).setValueInputOption("RAW").execute();
  </code></pre>
  
  <p>but I get the following error when calling <code>execute()</code>:</p>
  
  <pre class="lang-none prettyprint-override"><code>com.google.api.client.googleapis.json.GoogleJsonResponseException: 400 Bad Request
  {
    "code" : 400,
    "errors" : [ {
      "domain" : "global",
      "message" : "Invalid values[3][1]: struct_value {\n}\n",
      "reason" : "badRequest"
    } ],
    "message" : "Invalid values[3][1]: struct_value {\n}\n",
    "status" : "INVALID_ARGUMENT"
  }
      at com.google.api.client.googleapis.json.GoogleJsonResponseException.from(GoogleJsonResponseException.java:150)
      at com.google.api.client.googleapis.services.json.AbstractGoogleJsonClientRequest.newExceptionOnError(AbstractGoogleJsonClientRequest.java:113)
      at com.google.api.client.googleapis.services.json.AbstractGoogleJsonClientRequest.newExceptionOnError(AbstractGoogleJsonClientRequest.java:40)
      at com.google.api.client.googleapis.services.AbstractGoogleClientRequest$1.interceptResponse(AbstractGoogleClientRequest.java:321)
      at com.google.api.client.http.HttpRequest.execute(HttpRequest.java:1065)
      at com.google.api.client.googleapis.services.AbstractGoogleClientRequest.executeUnparsed(AbstractGoogleClientRequest.java:419)
      at com.google.api.client.googleapis.services.AbstractGoogleClientRequest.executeUnparsed(AbstractGoogleClientRequest.java:352)
      at com.google.api.client.googleapis.services.AbstractGoogleClientRequest.execute(AbstractGoogleClientRequest.java:469)
  </code></pre>
  
  <p>How can I solve this?</p>