void (*on_close) (void *, uint16_t code, size_t size);
void (*on_text) (void *, int last, size_t size);
void (*on_binary) (void *, int last, size_t size);
void (*on_continue) (void *, int last, size_t size);
int (*on_extension) (void *, int last, int rsv1, int rsv2, int rsv3, int opcode, size_t size);
void (*on_close) (void *, uint16_t code, size_t size);
void (*on_text) (void *, int last, size_t size);
void (*on_binary) (void *, int last, size_t size);
void (*on_continue) (void *, int last, size_t size);
int (*on_extension) (void *, int last, int rsv1, int rsv2, int rsv3, int opcode, size_t size);