### Question:
DataUtilities { public static Number[][] createNumberArray2D(double[][] data) { if (data == null) { throw new IllegalArgumentException("Null 'data' argument."); } int l1 = data.length; Number[][] result = new Number[l1][]; for (int i = 0; i < l1; i++) { result[i] = createNumberArray(data[i]); } return result; }  static boolean equal(double[][] a, double[][] b); static double[][] clone(double[][] source); static double calculateColumnTotal(Values2D data, int column); static double calculateColumnTotal(Values2D data, int column,
             int[] validRows); static double calculateRowTotal(Values2D data, int row); static double calculateRowTotal(Values2D data, int row,
             int[] validCols); static Number[] createNumberArray(double[] data); static Number[][] createNumberArray2D(double[][] data); static KeyedValues getCumulativePercentages(KeyedValues data);  }### Answer:
@Test public void testCreateNumberArray2D() { double[][] d = new double[2][]; d[0] = new double[] {1.1, 2.2, 3.3, 4.4}; d[1] = new double[] {1.1, 2.2, 3.3, 4.4, 5.5}; Number[][] n = DataUtilities.createNumberArray2D(d); assertEquals(2, n.length); assertEquals(4, n[0].length); assertEquals(5, n[1].length); }