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: lib.rs
    path of file: ./repos/bottlerocket/sources/api/thar-be-settings/src
    
    the code of the file until where you have to start completion: /*!
# Background

thar-be-settings is a simple configuration applier.
Its job is to update configuration files and restart services, as necessary, to make the system reflect any changes to settings.

In the
    
pub fn get_changed_settings() -> Result<HashSet<String>> {
    let mut input = String::new();
    io::stdin()
        .read_to_string(&mut input)
        .context(error::ReadInputSnafu { from: "stdin" })?;
    trace!("Raw input from stdin: {}", &input);

    // Settings should be a vec of strings
    debug!("Parsing stdin as JSON");
    let changed_settings: HashSet<String> =
        serde_json::from_str(&input).context(error::InvalidInputSnafu {
            reason: "Input must be a JSON array of strings",
            input,
        })?;
    trace!("Parsed input: {:?}", &changed_settings);

    Ok(changed_settings)
}