[Test]
public void CheckDefaultValues()
{
    Assert.AreEqual(new Vector2D(0.0f, 98.2f), physics.Gravity);
    Assert.AreEqual(0, physics.Bodies.Count());
}

[Test]
public void CheckDefaultValues()
{
    Assert.AreEqual(new Vector2D(0.0f, 98.2f), physics.Gravity);
    Assert.AreEqual(0, physics.Bodies.Count());
}

[Test]
public void ChangeGravity()
{
    physics.Gravity = Vector2D.UnitY;
    Assert.AreEqual(Vector2D.UnitY, physics.Gravity);
}

[Test]
public void ChangeGravity()
{
    physics.Gravity = Vector2D.UnitY;
    Assert.AreEqual(Vector2D.UnitY, physics.Gravity);
}

[Test]
public void CreateBody()
{
    VerifyBodyIsCreated(physics.CreateRectangle(Size.One));
}

[Test]
public void CreateBody()
{
    VerifyBodyIsCreated(physics.CreateRectangle(Size.One));
}

[Test]
public void CreateEdge()
{
    VerifyBodyIsCreated(physics.CreateEdge(Vector2D.Zero, Vector2D.One));
}

[Test]
public void CreateEdge()
{
    VerifyBodyIsCreated(physics.CreateEdge(Vector2D.Zero, Vector2D.One));
}

[Test]
public void CreateEdgeMultiPoints()
{
    VerifyBodyIsCreated(physics.CreateEdge(Vector2Ds));
}

[Test]
public void CreateEdgeMultiPoints()
{
    VerifyBodyIsCreated(physics.CreateEdge(Vector2Ds));
}

[Test]
public void CreatePolygon()
{
    VerifyBodyIsCreated(physics.CreatePolygon(Vector2Ds));
}

[Test]
public void CreatePolygon()
{
    VerifyBodyIsCreated(physics.CreatePolygon(Vector2Ds));
}

[Test]
public void CheckWorldIsSimulated()
{
    var body = physics.CreateRectangle(Size.One);
    AdvanceTimeAndUpdateEntities();
    Assert.AreNotEqual(Vector2D.Zero, body.Position);
}

[Test]
public void CheckWorldIsSimulated()
{
    var body = physics.CreateRectangle(Size.One);
    AdvanceTimeAndUpdateEntities();
    Assert.AreNotEqual(Vector2D.Zero, body.Position);
}