I need help implementing the following Java code

package mini2;

import api.ITransform;

/** * Utility class for applying transformations to 2d arrays. * A transformation computes a new value for a cell that is * based on the square neighborhood of cells that surround it. * Each transformation is an implementation of * the ITransform interface. */ public class GridUtil { /** * Applies the given transformation to all cells of the given * array and produces a new array of the same size. The original * array is not modified. * @param arr * given array * @param transform * transformation to apply * @return * new array consisting of transformed values */ public static int[][] applyAll(int[][] arr, ITransform transform) { // THIS METHOD IS FULLY IMPLEMENTED AND SHOULD NOT BE MODIFIED int numRows = arr.length; int numCols = arr[0].length; int[][] result = new int[numRows][numCols]; for (int row = 0; row < numRows; row += 1) { for (int col = 0; col < numCols; col += 1) { int[][] subArray = getSubArray(arr, row, col, transform.getRadius(), transform.isWrapped()); int newValue = transform.apply(subArray); result[row][col] = newValue; } } return result; } /** * Displays the contents of a 2d int array * @param arr * a 2d array of ints */ public static void printArray(int[][] arr) { for (int row = 0; row < arr.length; row += 1) { for (int col = 0; col < arr[0].length; col += 1) { System.out.printf("%3d", arr[row][col]); } System.out.println(); } } /** * Returns the neighborhood surrounding the specified cell. In general, * the returned array is a square sub-array of arr, * with width and height 2 * radius + 1, whose center is * arr[centerRow][centerCol]. For cells within * radius of the edge, the value for out-of-range * indices is determined by * the wrapped parameter, as follows: *

*
• if wrapped is false, cells for out-of-range indices * are filled with zeros *
• if wrapped is true, cells for out-of-range indices * are determined by "wrapping" the indices: *
  *
  • for a row index, the array height is added to or subtracted from the index * to bring it within range *
  • for a column index, the array width is added to or subtracted from * the index to bring it within range *
  *

* Note that the size of neighborhood, neighborhood size 2 * radius + 1, * is not allowed to be greater than either the width or height of the given array. * @param arr * the original array * @param centerRow * row index of center cell * @param centerCol * column index of center cell * @param radius * radius of the neighborhood (return array has width and height * equal to 2 * radius + 1 * @param wrapped * true if out-of-range indices should be wrapped, false if cells * should be filled with zeros * @return * a new 2d array consisting of the cells surrounding the given center * cell * @throws IllegalArgumentException * if the neighborhood size 2 * radius + 1 is greater * than the given array's width or height */ public static int[][] getSubArray(int[][] arr, int centerRow, int centerCol, int radius, boolean wrapped) { // TODO return null; } }