@Override
	public int childCount() {
		if (_left != null) {
			return _right != null ? 2 : 1;
		} else {
			return _right != null ? 1 : 0;
		}
	}
Sets the user object for this node.

@param value the node {@code value}
jenetics.incubator/src/main/java/io/jenetics/incubator/util/BinaryTree.java