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: mod.rs
    path of file: ./repos/vopono/vopono_core/src/config/providers
    
    the code of the file until where you have to start completion: mod airvpn;
mod azirevpn;
mod hma;
mod ivpn;
mod mozilla;
mod mullvad;
mod nordvpn;
pub mod pia;

    
    pub fn get_dyn_shadowsocks_provider(&self) -> anyhow::Result<Box<dyn ShadowsocksProvider>> {
        match self {
            Self::Mullvad => Ok(Box::new(mullvad::Mullvad {})),
            Self::Custom => Err(anyhow!("Start Shadowsocks manually for custom provider")),
            Self::Warp => Err(anyhow!("Cloudflare Warp supports only the Warp protocol")),
            Self::None => unimplemented!("None provider runs no protocol"),
            _ => Err(anyhow!("Shadowsocks not supported")),
        }
    }