d3x-morpheus DataFrame row/column removal issue

DataFrameRowColRemoval.java

import com.d3x.morpheus.array.Array;
import com.d3x.morpheus.frame.DataFrame;
import com.d3x.morpheus.frame.DataFrameValue;

import java.util.List;

public class DataFrameRowColRemoval {
    public static void main(String[] args) {
        new DataFrameRowColRemoval();
    }

    private DataFrameRowColRemoval(){
        final var rows = Array.of(0, 1, 2, 3, 4);
        final var cols = Array.of('A', 'B', 'C', 'D', 'E', 'F');
        final var colsToRemove = List.of('B', 'D', 'F');
        final var rowsToRemove = List.of(0, 1);
        final var frame = DataFrame.ofInts(rows, cols);

        frame.applyValues(this::generateValue);
        print("Frame before column removal", frame);

        final var newFrame =
                frame.cols().remove(col -> colsToRemove.contains(col.key()))
                     .rows().remove(row -> rowsToRemove.contains(row.key()));
        print("Frame after column removal", newFrame);
    }

    private void print(String title, DataFrame<Integer, Character> frame) {
        System.out.println(title);
        System.out.print("     ");
        frame.cols().forEach(col -> System.out.printf("%3c ", col.key()));
        System.out.println();

        frame.rows().forEach(row -> {
            System.out.printf("%2d | ", row.key());
            row.forEach(val -> System.out.printf("%3d ", val.getInt()));
            System.out.println();
        });
        System.out.println();
    }

    private int generateValue(DataFrameValue<Integer, Character> val){
        return (val.rowOrdinal() + val.colOrdinal() * val.frame().rowCount()) + 1;
    }
}