You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: statement_cache.rs
    path of file: ./repos/sqlx/sqlx-core/src/common
    
    the code of the file until where you have to start completion: use hashlink::lru_cache::LruCache;

/// A cache for prepared statements. When full, the least recently used
/// statement gets removed.
#[derive(Debug)]
pub struct StatementCache<T> {
    inner: LruCache
    
    pub fn insert(&mut self, k: &str, v: T) -> Option<T> {
        let mut lru_item = None;

        if self.capacity() == self.len() && !self.contains_key(k) {
            lru_item = self.remove_lru();
        } else if self.contains_key(k) {
            lru_item = self.inner.remove(k);
        }

        self.inner.insert(k.into(), v);

        lru_item
    }