GOOGLE DOCS API Invalid requests[0].updateTextStyle: Index 4 must be less than the end index of the referenced segment, 2.", - api

Question

I've created a document using Google Docs API, but when I try to modify its options or add text, it gives me this error:
http://prntscr.com/naf0nm
The thing is if I open the document and click enter many times ( to make many lines) then execution and modification works. Can anyone help me?? What do I need to do to not get this error?
String text1 = "hola, llegó papa";
List<Request> requests = new ArrayList<>();
requests.add(new Request().setInsertText(new InsertTextRequest()
.setText(text1)
.setLocation(new Location().setIndex(25))));
BatchUpdateDocumentRequest body = new BatchUpdateDocumentRequest().setRequests(requests);
BatchUpdateDocumentResponse response = service.documents()
.batchUpdate(idDoc, body).execute();
Here the method to create doc:
private static void createDoc(Docs service) throws IOException {
Document doc = new Document()
.setTitle("TEXTO CAMBIADO");
doc = service.documents().create(doc)
.execute();
System.out.println("Created document with title: " + doc.getTitle());
idDoc = doc.getDocumentId();
}

Answer 1

It is very late for answer but it can help to others.
May be this answer can help you. someone has answered here
Also you have to write backword to get the last inserted text at the starting of doc.
I just found another way to write text at end of doc. You don't need to set the location, just do this way..
public void insertText(Docs docsService) throws IOException {
List<Request> requests = new ArrayList<>();
requests.add(new Request().setInsertText(new InsertTextRequest()
.setText("Name : {{NAME}}\n")
.setEndOfSegmentLocation(new EndOfSegmentLocation())));
requests.add(new Request().setInsertText(new InsertTextRequest()
.setText("\nDOB: {{DOB}}\n")
.setEndOfSegmentLocation(new EndOfSegmentLocation())));
requests.add(new Request().setInsertText(new InsertTextRequest()
.setText("\nMobile: {{MOBILE}}\n")
.setEndOfSegmentLocation(new EndOfSegmentLocation())));
BatchUpdateDocumentRequest body = new BatchUpdateDocumentRequest().setRequests(requests);
BatchUpdateDocumentResponse response = docsService.documents()
.batchUpdate(Constants.DOCUMENT_ID, body).execute();
}