pub fn as_raw_cow(&self) -> Cow<'a, str> {
        match &self.raw {
            JsonSlice::Raw(r) => Cow::Borrowed(unsafe { from_utf8_unchecked(r) }),
            JsonSlice::FastStr(f) => Cow::Owned(f.to_string()),
        }
    }
Export the raw JSON text as `Cow<'de, str>`.  The lifetime `'de` is the origin JSON.

# Examples

```
use sonic_rs::{get, LazyValue};

let lv: LazyValue = sonic_rs::get(r#"{"a": "hello world"}"#, &["a"]).unwrap();
assert_eq!(lv.as_raw_cow(), "\"hello world\"");
```
src/lazyvalue/value.rs