pub unsafe extern "C" fn coap_persist_observe_add(
context: *mut coap_context_t,
e_proto: coap_proto_t,
e_listen_addr: *const coap_address_t,
s_addr_info: *const coap_addr_tuple_t,
raw_packet: *const coap_bin_const_t,
oscore_info: *const coap_bin_const_t,
) -> *mut coap_subscription_t