Exception when attempting to set Select property to nothing.

[Scantheus]

You can set a Select property to nothing by set the PropertyValue to null.
However, if you try to include another Select property with a value, it generates an exception.

Consider a table with two Select properties named "SelectProperty1" and "SelectProperty2".
Set one property to null and another to a value.
This generates an exception. If you call UpdateSync with only one of the properties, it works.

Dictionary<string, PropertyValue> updateProperties = new Dictionary<string, PropertyValue>();
updateProperties.Add("SelectProperty1", null);
updateProperties.Add("SelectProperty2, new SelectPropertyValue() { Select = new SelectOption() { Name = "SelectValue1" } });

try
{
await Client.Pages.UpdateAsync(pageId, new PagesUpdateParameters() { Properties = updateProperties });
}
catch (NotionApiException ex)
{
Debug.WriteLine($"Exception : Status Code {ex.StatusCode}, API Error {ex.NotionAPIErrorCode} : {ex.Message}";
}
catch (Exception ex)
{
Debug.WriteLine(ex.Message);
}

Resulting Exception:
Exception : Status Code BadRequest, API Error ValidationError : body failed validation. Fix one:
body.properties.SelectProperty2.id should be defined, instead was 'undefined'.
body.properties.SelectProperty2.name should be defined, instead was 'undefined'.
body.properties.SelectProperty2.start should be defined, instead was 'undefined'.

SelectEmptyBug.txt

[Scantheus]

Looking through open issues, this looks related to #345.

[KoditkarVedant]

@Scantheus I'm unable to spend time on the library in recent past. In case you would like to raise a PR for this I would be very much happy to accept it.

[KoditkarVedant]

@Scantheus I tried producing this on local using SDK and Postman - found that this is something related to Notion API.

That being said Notion API expect the ``SelectPropertyValue.Select to be null (to reset values when updating multiple properties at once) - I noticed if you set theSelectPropertyValue.Select` property null the library ignore null which I have fixed it in PR - #355