+ /**
+ * This method does the actual planning. Given the input node it will
+ * try to find all preconditions and create links from parent nodes
+ * to this node and, if the precondition did not have a node associated
+ * with it, create a new and recursively call this method for the newly
+ * created node.
+ *
+ * @param node The node which this method will find parent nodes for.
+ */