Possible problem with google sheets api v4 - google-sheets-api

Question

I am trying to update a specific range using the sheets API (https://developers.google.com/sheets/api/reference/rest/v4/spreadsheets.values/update):
The body of the update request must be a ValueRange object, though the only required field is values. If range is specified, it must match the range in the URL. In the ValueRange, you can optionally specify its majorDimension. By default, ROWS is used. If COLUMNS is specified, each inner array is written to a column instead of a row.When updating, values with no data are skipped. To clear data, use an empty string ("").
When I try to update specific cells by sending data, like this one :
[
[null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, 5523, null, null, null, null, null, null, null, P],
[null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, 5526, null, null, null, null, null, null, null, P]
]
The range is "SheetName!A2:AA3".
The cells that are updated are A2 B2 and A3 B3.
Any idea why this happens?
Thank you.
Here is an example that leads to this problem:
The table initially is:
The code is:
String spreasheetId = "<SpreadsheetId>";
ValueRange valueRange = new ValueRange();
valueRange.setRange("Sheet15!A2:C4");
valueRange.setMajorDimension("ROWS");
List<Object> ob = Arrays.asList(null,"4",null);
List<Object> ob1 = Arrays.asList(null,"10",null);
List<List<Object>> list = Arrays.asList(ob,new ArrayList<>(),ob1);
valueRange.setValues(list);
sheetService.spreadsheets().values().update(spreasheetId, valueRange.getRange(), valueRange).setValueInputOption("RAW").execute();
The table after I run the code is this:
While it should be:

Answer 1

From the official documentation, in the setValues() area:
For input, supported value types are: bool, string, and double. Null values will be skipped. To set a cell to an empty value, set the string value to an empty string.
Thus, values set to null are essentially not interpreted, and the result you obtain is as if your range was created as follows:
List<Object> ob = Arrays.asList("4");
List<Object> ob1 = Arrays.asList("10");
List<List<Object>> list = Arrays.asList(ob,new ArrayList<>(),ob1);
valueRange.setValues(list);
To attain the objectives you defined in your original question, you will have to:
Obtain the current data in the sheet.
Modify it as appropriately.
Set it back to the sheet.
Your final code could look like the following:
String spreadsheetId = "<SpreadsheetId>";
ValueRange currentRange = service.spreadsheets().values().get(spreadsheetId, "A2:C4").execute();
List<List<Object>> myValues = currentRange.getValues();
myValues.get(0).set(1, "4");
myValues.get(2).set(1, "10");
ValueRange resultRange = new ValueRange().setMajorDimension("ROWS").setValues(myValues);
service.spreadsheets().values().update(spreadsheetId, "A2:C4", resultRange).setValueInputOption("RAW").execute();