@@ -0,0 +1,1216 @@
+package com.google.research.bleth.simulator;%0A%0Aimport java.util.ArrayList;%0Aimport java.util.Arrays;%0A%0A/** A container for all the agents, representing their locations, either real or estimated. */%0Apublic class Board %7B%0A    public final int rowNum;%0A    public final int colNum;%0A    ArrayList%3CAgent%3E%5B%5D%5B%5D matrix;%0A%0A    public Board(int rows, int cols) %7B%0A        rowNum = rows;%0A        colNum = cols;%0A        matrix = new ArrayList%5BrowNum%5D%5BcolNum%5D;%0A        for (int row = 0; row %3C rows; row++) %7B%0A            Arrays.setAll(matrix%5Brow%5D, ArrayList::new);%0A        %7D%0A    %7D%0A%0A    /** Place an agent on board if the given location is valid. */%0A    public void placeAgent(Location newLocation, Agent agent) %7B%0A        boolean isRowValid = newLocation != null && 0 %3C= newLocation.row && newLocation.row %3C rowNum;%0A        boolean isColValid = newLocation != null && 0 %3C= newLocation.col && newLocation.col %3C colNum;%0A        if (isRowValid && isColValid) %7B%0A            matrix%5BnewLocation.row%5D%5BnewLocation.col%5D.add(agent);%0A        %7D%0A    %7D%0A%0A    /** Remove an agent from its current location on board and place it on new location. */%0A    public void moveAgent(Location oldLocation, Location newLocation, Agent agent) %7B%0A        //%0A    %7D%0A%7D%0A%0A%0A

Add the class Board, implement its method placeAgent.