code: public boolean addObject (ObjectInfo info)
      {
          // make sure we don't already have this same object at these
          // coordinates
          for (SceneObject _object : _objects) {
              if (_object.info.equals(info)) {
                  return false;
              }
          }
  
          _objects = ArrayUtil.append(_objects, makeSceneObject(info));
  
          // clear out our neighbors array so that the subsequent update
          // causes us to recompute our coverage
          Arrays.fill(_neighbors, null);
          return true;
      }
docs: Adds the supplied object to this block. Coverage is not computed
  for the added object, a subsequent call to {@link #update} will be
  needed.
  
  @return true if the object was added, false if it was not because
  another object of the same type already occupies that location.