Errors on HistogramAlphabet with Map function [closed]

I have fixed all of the errors from the previous code but when I try to run my program I get the following errors from my terminal

"java.lang.reflect.InvocationTargetException at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:116) at java.base/java.lang.reflect.Method.invoke(Method.java:577) at javafx.graphics@18.0.1/com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:465) at javafx.graphics@18.0.1/com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:364) at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104) at java.base/java.lang.reflect.Method.invoke(Method.java:577) at java.base/sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:1081) Caused by: java.lang.NullPointerException: Cannot invoke "java.util.Map.put(Object, Object)" because "this.slicePieChart" is null at com.example.assignment3/com.example.assignment3.HistogramAlphabet$myPieChart.getMyPieChart(HistogramAlphabet.java:131) at com.example.assignment3/com.example.assignment3.HistogramAlphabet$myPieChart.(HistogramAlphabet.java:114) at com.example.assignment3/com.example.assignment3.Assignment3.readFile(Assignment3.java:61) at com.example.assignment3/com.example.assignment3.Assignment3.main(Assignment3.java:93) at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104) ... 6 more Exception running application com.example.assignment3.Assignment3"

for reference: here's the codes that are being problematic

in HistogramAlphabet.java, my inner class myPieChart

public class myPieChart{

    Map<Character, Slice> slicePieChart;
    public Map<Character, Slice> getMyPieChart;



    int N;
    myPoint center;
    int radius;
    double rotateAngle;

    myColor[] color;


    myPieChart(int N, myPoint center, int radius, double rotateAngle, myColor[] color){
        this.N = N;
        this.center = center;
        this.radius = radius;
        this.color = color;
        this.rotateAngle = Optional.ofNullable(rotateAngle).orElse(0.0);

        probability = getProbability();
        slicePieChart = getMyPieChart();
    }




    public Map<Character, Slice> getMyPieChart(){

        myColor[] colors = myColor.getMyColors();

        Random rand = new Random();
        int colorsSize = colors.length;

        double startAngle = rotateAngle;
        for(Character Key: probability.keySet()) {

            double angle = 360.0 * probability.get(Key);
            slicePieChart.put(Key, new Slice(center, radius, startAngle, angle, new myColor[]{colors[rand.nextInt(colorsSize)]}));
        }
        return  slicePieChart;
    }

and here is Assignment3.java that's been causing issues

public static void readFile() {

    try {
        String w = "";
        while (input.hasNext()) {
            w += input.nextLine().replaceAll("[^a-zA-Z]", "").toLowerCase();
        }

        System.out.println("\nNumber of Characters: " + w.length() + "\n");

        HistogramAlphabet H = new HistogramAlphabet(w);
        Map<Character, Integer> sortedFrequency = H.sortDownFrequency();

        sortedFrequency.forEach((K, V) -> System.out.println(K + ": " + V));
        System.out.println("\nCumulative Frequency: " + H.getCumulativeFrequency() + "\n");
        System.out.println("\nNumber of Characters: " + sortedFrequency.values().stream().reduce(0, (x,y)-> x +y)+ "\n");

        HistogramAlphabet.myPieChart piechart = H.new myPieChart(0, new myPoint(100,100), 50, 30.0, color);
        System.out.println(H.getProbability());
        System.out.println("\nSum of Probabilities: " + H.getSumOfProbability() + "\n");

        Map<Character, Slice> slices = piechart.getMyPieChart;
        sortedFrequency.forEach((K,V) -> System.out.println(K + ": " + slices.get(K)));

        double sumofangles = 0.0;
        for(Character key : slices.keySet()){ sumofangles += slices.get(key).getAngle();}
        System.out.println("\nSum of Angles: " + sumofangles);

    } catch (NoSuchElementException elementException) {
        System.err.println("Invalid Input! Terminating....");
    } catch (IllegalStateException stateException) {
        System.out.println("Error processing file! Terminating...");
    }




}