public void GetDirection()
{
var up = MabiMath.DegreeToRadian(90);
var down = MabiMath.DegreeToRadian(270);
var left = MabiMath.DegreeToRadian(180);
var right = MabiMath.DegreeToRadian(0);
var pos = new Position(100, 100);
Assert.Equal(up, pos.GetDirection(new Position(100, 200)));
Assert.Equal(down, pos.GetDirection(new Position(100, 0)));
Assert.Equal(left, pos.GetDirection(new Position(0, 100)));
Assert.Equal(right, pos.GetDirection(new Position(200, 100)));
}