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: name.rs
    path of file: ./repos/polars/crates/polars-plan/src/dsl
    
    the code of the file until where you have to start completion: #[cfg(feature = "dtype-struct")]
use smartstring::alias::String as SmartString;

use super::*;

/// Specialized expressions for modifying t
    
    /// fn example(df: LazyFrame) -> LazyFrame {
    ///     df.select([
    /// // even thought the alias yields a different column name,
    /// // `keep` will make sure that the original column name is used
    ///         col("*").alias("foo").name().keep()
    /// ])
    /// }