You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: AstarPO.m
    path of file: ./repos/robotics-toolbox-matlab
    
    the code of the file until where you have to start completion: % AstarPO (A*-PO)
% A*PO navigation class
% 
% A concrete subclass of the Navigation class that implements the A*
% navigation algorithm for multiobjective optimization (MOO) - i.e.
% optimizes over several objectives/criteria.
% 
% Methods::
% plan              Compute the cost map given a goal and map
% path              Compute a path to the goal
% visualize         Display the obstacle 
    
function c = heurstic_get(as)
        %AstarPO.heuristice_get Get the current heuristic map
        %
        % C = AS.heuristice_get() is the current heuristic map.  This map is the same size
        % as the occupancy grid and the value of each element is the shortest distance 
        % from the corresponding point in the map to the current goal.  It is computed
        % by Astar.plan.
        %
        % See also Astar.plan.
            c = as.cost_h;
        end