Function heartbeats_simple_sys::heartbeat_pow

pub unsafe extern fn heartbeat_pow(hb: *mut heartbeat_pow_context,
                                   user_tag: uint64_t,
                                   work: uint64_t,
                                   start_time: uint64_t,
                                   end_time: uint64_t,
                                   start_energy: uint64_t,
                                   end_energy: uint64_t)