@Test
  public void testLengthTrue() {
    // arrange
    Point _pointA = new Point(2, 5);
    Point _pointB = new Point(5, 9);
    double expected = 5;

    LineSegment _arcAB = new LineSegment(_pointA, _pointB);

    // act
    double reached = _arcAB.length();

    // assert
    boolean result = (expected == reached);
    assertTrue(result);
  }
  @Test
  public void testEqualsLineSegmentTheSameFalse2() {
    // arrange
    Point _pointA = new Point(5, 5);
    Point _pointB = new Point(2, 2);

    Point _pointC = new Point(2, 2);
    Point _pointD = new Point(4, 4);

    LineSegment _arcAB = new LineSegment(_pointA, _pointB);
    LineSegment _arcCD = new LineSegment(_pointC, _pointD);
    boolean expected = false;

    // act
    boolean reached = _arcAB.equals(_arcCD);

    // assert
    boolean result = !(expected ^ reached);
    assertTrue(result);
  }
  @Test
  public void testShiftLineSegmentFalse() {
    // arrange
    Point _pointA = new Point(2, 2);
    Point _pointB = new Point(4, 4);
    boolean expected = false;
    LineSegment _arcAB = new LineSegment(_pointA, _pointB);

    Point _pointAAfter = new Point(4, 4);
    Point _pointBAfter = new Point(8, 8);
    LineSegment _arcABShifted = new LineSegment(_pointAAfter, _pointBAfter);

    // act
    _arcAB.shift(2, 2);
    boolean reached = _arcAB.equals(_arcABShifted);

    // assert
    boolean result = !(expected ^ reached);
    assertTrue(result);
  }