public void TestGetTextureGroupForPoint()
        {
            var textureGroupResolver   = new HeightmapTextureGroupResolver(_mockHeightmap, _mockTextureGroupRepository);
            var upperLeftTextureGroup  = new TextureGroupRange(0, 50);
            var upperRightTextureGroup = new TextureGroupRange(51, 150);
            var lowerLeftTextureGroup  = new TextureGroupRange(151, 200);
            var lowerRightTextureGroup = new TextureGroupRange(201, 255);

            _mockTextureGroupRepository.Add(upperLeftTextureGroup);
            _mockTextureGroupRepository.Add(upperRightTextureGroup);
            _mockTextureGroupRepository.Add(lowerLeftTextureGroup);
            _mockTextureGroupRepository.Add(lowerRightTextureGroup);


            var textureGroup = textureGroupResolver.GetTextureGroupForPoint(0, 0);

            Assert.AreSame(upperLeftTextureGroup, textureGroup);

            textureGroup = textureGroupResolver.GetTextureGroupForPoint(5, 0);
            Assert.AreSame(upperRightTextureGroup, textureGroup);

            textureGroup = textureGroupResolver.GetTextureGroupForPoint(0, 5);
            Assert.AreSame(lowerLeftTextureGroup, textureGroup);

            textureGroup = textureGroupResolver.GetTextureGroupForPoint(5, 5);
            Assert.AreSame(lowerRightTextureGroup, textureGroup);
        }