h2span_node
RB_HEAD(h2span_node_tree, h2span_node);
RB_ENTRY(h2span_node) rbnode;
struct h2span_node *node; /* related node */
typedef struct h2span_node h2span_node_t;
RB_PROTOTYPE_STATIC(h2span_node_tree, h2span_node,
RB_GENERATE_STATIC(h2span_node_tree, h2span_node,