What is the difference between returning the solution and returning an initialized array ?

In line 20, I wanted to return return new Number[]{4,5,6}; but the mentor wouldn't accept my version. Why is that?

package com.codegym.task.task37.task3706;

import java.util.Arrays;
import java.util.List;

/*
The long forgotten Array

*/

public class Solution {
    public static void main(String[] args) {
        List<Number> numbers = Arrays.<Number>asList(1, 2, 3);
        addDataToList(numbers, getData());
        System.out.println(numbers);
    }

    public static Number[] getData() {

        return new Number[]{};
    }

    public static void addDataToList(List<Number> list, Number... data) {
        for (Number number : data) {
            list.add(number);
        }
    }
}

The long forgotten Array Implement the getData method so that the main method finishes without throwing exceptions. Don't change the rest of the code. Requirements: 1. The getData method must not return null. 2. The getData method must return an object that satisfies the task conditions. 3. The getData method must be public. 4. The getData method must be static.