I enabled rust_analyzer in astronvim, when ParseIntError is not found in this scope, I want to add the import automaticlly.

With Goland, I can use Alt + Enter to see available import, how can I achive this in astronvim? 

```
fn try_to_parse() -> Result<i32, ParseIntError> {     // cannot find type `ParseIntError` in this scope not found in this scope
    let x: i32 = "100".parse()?;
    let y: i32 = "10a".parse()?;
    Ok(x + y)
}
```