how to support struct type value

hi,
I also want to discuss a issue, whether it is possible to use struct type for value,
although I see in tcp-window-clamps.bpf.c

```c
struct socktest {
u32 value1;
u32 value2;
u32 value3;
}
struct {
__uint(type, BPF_MAP_TYPE_LRU_HASH);
__uint(max_entries, 1024);
__type(key, u64);
__type(value, struct socktest *);
} tcp_rmem_schedule_enters SEC(".maps");
```

but it don't use by metrics .
Currently, it seems that a struct type cannot be supported, and it can parse multiple member values.

Can you explain this problem, thanks!