+/**
+ * @brief Return already stacked up next node index for a given
+ * child_type/child_proto and parent_type/patent_proto.
+ * The VLIB graph arc used is taken from the parent and child types
+ * passed.
+ *
+ * @param child_type
+ * Child DPO type.
+ *
+ * @param child_proto
+ * Child DPO proto
+ *
+ * @param parent_type
+ * Parent DPO type.
+ *
+ * @param parent_proto
+ * Parent DPO proto
+ *
+ * @return The VLIB Graph node index
+ */
+extern u32
+dpo_get_next_node_by_type_and_proto (dpo_type_t child_type,
+ dpo_proto_t child_proto,
+ dpo_type_t parent_type,
+ dpo_proto_t parent_proto);