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/vaultwarden/src/api
    
    the code of the file until where you have to start completion: mod admin;
pub mod core;
mod icons;
mod identity;
mod notifications;
mod push;
mod web;

use rocket::serd
    
    pub async fn validate(&self, user: &User, delete_if_valid: bool, conn: &mut DbConn) -> EmptyResult {
        use crate::api::core::two_factor::protected_actions::validate_protected_action_otp;

        match (self.MasterPasswordHash.as_deref(), self.Otp.as_deref()) {
            (Some(pw_hash), None) => {
                if !user.check_valid_password(pw_hash) {
                    err!("Invalid password");
                }
            }
            (None, Some(otp)) => {
                validate_protected_action_otp(otp, &user.uuid, delete_if_valid, conn).await?;
            }
            _ => err!("No validation provided"),
        }
        Ok(())
    }