code: public GridNode getNodeAt( Direction direction ) {
          int newCol = col + direction.col;
          int newRow = row + direction.row;
          GridNode node = new GridNode(gridIter, cols, rows, xRes, yRes, newCol, newRow);
          return node;
      }
docs: Get a neighbor node at a certain direction.
  
  @param direction the direction to get the node at.
  @return the node.