void checkOffset(
double x0,
double y0,
double x1,
double y1,
double segFrac,
double offset,
double expectedX,
double expectedY) {
LineSegment seg = new LineSegment(x0, y0, x1, y1);
Coordinate p = seg.pointAlongOffset(segFrac, offset);
assertTrue(equalsTolerance(new Coordinate(expectedX, expectedY), p, 0.000001));
}
