Test class of SLAPI's chart API

TestListener.java

package de.geolykt.starloader;

import java.util.Objects;

import org.jetbrains.annotations.NotNull;

import de.geolykt.starloader.api.Galimulator;
import de.geolykt.starloader.api.empire.ActiveEmpire;
import de.geolykt.starloader.api.empire.Empire;
import de.geolykt.starloader.api.event.EventHandler;
import de.geolykt.starloader.api.event.Listener;
import de.geolykt.starloader.api.event.lifecycle.LogicalTickEvent;
import de.geolykt.starloader.api.event.lifecycle.LogicalTickEvent.Phase;
import de.geolykt.starloader.api.gui.Drawing;
import de.geolykt.starloader.api.gui.Dynbind;
import de.geolykt.starloader.api.gui.graph.LineChartComponentSupplier;
import de.geolykt.starloader.api.gui.graph.RollingChartData;
import de.geolykt.starloader.api.gui.screen.ComponentSupplier;
import de.geolykt.starloader.api.gui.screen.LineWrappingInfo;
import de.geolykt.starloader.api.gui.screen.Screen;
import de.geolykt.starloader.api.gui.screen.ScreenBuilder;
import de.geolykt.starloader.api.gui.text.TextColor;

public class TestListener implements Listener {

    private class ShowScienceChartKeybind implements Dynbind {

        private Screen screen;

        @Override
        public @NotNull String getDescription() {
            return "Shows a chart with the science levels of the empires.";
        }

        @Override
        public @NotNull String getKeyDescription() {
            return "Shift + S";
        }

        @Override
        public boolean isValidChar(char character) {
            return character == 'S';
        }

        @Override
        public boolean isValidKeycode(int key) {
            return false;
        }

        @Override
        public void performAction() {
            if (screen == null) {
                ScreenBuilder builder = ScreenBuilder.getBuilder();
                LineWrappingInfo lwInfo = new LineWrappingInfo(false, false, false, false);
                ComponentSupplier supplier = new LineChartComponentSupplier(scienceLevels, lwInfo, 800, 500);
                builder.addComponentSupplier(supplier);
                builder.setHeaderColor(TextColor.DARK_GREEN);
                builder.setHeaderEnabled(true);
                builder.setTitle("Science Graph test");
                builder.setWidth(820);
                screen = builder.build();
            }
            Drawing.showScreen(Objects.requireNonNull(screen));
        }
    }

    private @NotNull RollingChartData<Empire> scienceLevels = new RollingChartData<>(10_000);

    public TestListener() {
        Galimulator.registerKeybind(new ShowScienceChartKeybind());
    }

    @EventHandler
    public void onTick(LogicalTickEvent event) {
        if (event.getPhase() == Phase.PRE_LOGICAL && (Galimulator.getGameYear() % 100) == 0) {
            scienceLevels.incrementPosition();
            for (ActiveEmpire e : Galimulator.getEmpires()) {
                scienceLevels.addNode(e, e.getTechnologyLevel());
            }
        }
    }
}