@Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        } else if (!(obj instanceof Dimension)) {
            return false;
        }
        Dimension other = (Dimension) obj;
        if (this.width != other.width) {
            return false;
        } else if (this.height != other.height) {
            return false;
        }
        return true;
    }
@Test
    public void equalsTest() {
        Dimension dimension1 = new Dimension(1, 2);
        Dimension dimension2 = new Dimension(1, 2);
        Dimension dimension3 = new Dimension(1, 1);
        Dimension dimension4 = new Dimension(2, 2);

        TestUtils.equalsTest(dimension1, dimension2);

        TestUtils.notEqualsTest(dimension1, dimension3);
        TestUtils.notEqualsTest(dimension1, dimension4);
        TestUtils.notEqualsTest(dimension1, new Object());
        TestUtils.notEqualsTest(dimension1, null);
    }