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: payment_link.rs
    path of file: ./repos/hyperswitch/crates/router/src/core
    
    the code of the file until where you have to start completion: use api_models::{admin as admin_types, payments::PaymentLinkStatusWrap};
use common_utils::{
    consts::{
        DEFAULT_BACKGROUND_COLOR, DEFAULT_MERCHANT_LOGO, DEFAULT_PRODUCT_IMG, DEFAULT_SDK_LAYOUT,
        DEFAULT_SESSION_EXPIRY,
    },
    ext_traits::{OptionExt, ValueExt},
};
use error_stack::{IntoR
    
fn capitalize_first_char(s: &str) -> String {
    if let Some(first_char) = s.chars().next() {
        let capitalized = first_char.to_uppercase();
        let mut result = capitalized.to_string();
        if let Some(remaining) = s.get(1..) {
            result.push_str(remaining);
        }
        result
    } else {
        s.to_owned()
    }
}