@MIchaelMainer In BaseOnenotePageCollectionRequest
public void post(final OnenotePage newOnenotePage, final ICallback<OnenotePage> callback) {
is replaced with
public void post(final byte[] newOnenotePage, final ICallback<OnenotePage> callback) {
gen.zip
The newer folder shows that what will be directory stucture and class contents now.

I don't see the overwrite in OnenotePageCollectionRequest. Perhaps I'm missing something here.

One issue I do see are the namespace imports instead of only importing the required resources:

import com.microsoft.graph.concurrency.;
import com.microsoft.graph.core.;
import com.microsoft.graph.models.;
import com.microsoft.graph.http.;
import com.microsoft.graph.requests.;
import com.microsoft.graph.options.;
import com.microsoft.graph.serializer.*;
import java.util.Arrays;
import java.util.EnumSet;

Let's put this in another PR.