/** * Obtains the tree node corresponding to the specified cell * * @param cell * the cell whose tree node is to be found * @return the matching tree node, if any */ protected StandardTreeNode getTreeNode(Object cell) { if (cell != null) { StandardTreeNode node = (StandardTreeNode) nodes.get(cell); if (node == null) { node = new StandardTreeNode(cell); nodes.put(cell, node); } return node; } return null; }