public void FloorPlan_detects_agents()
        {
            FloorPlan plan = new FloorPlan();            //NSubstitute.Substitute.For<FloorPlan>();

            plan.FloorTiles.AddRange(_FillArea(30, 10, 1));
            plan.IsAgentOnTile(11, 4).Should().BeFalse();

            var agent = new Agent();            // NSubstitute.Substitute.For<IAgent>();

            agent.Move(new Location(11, 4));

            plan.AddAgent("Test Agent", agent);
            plan.IsAgentOnTile(11, 4).Should().BeTrue();

            plan.IsAgentOnTile(4, 11).Should().BeFalse();
        }