js_class 属性可以与 method 属性一起使用，以绑定已在 Rust 端重命名的导入 JavaScript 类的 方法。

# #![allow(unused_variables)]
#fn main() {
#[wasm_bindgen]
extern "C" {
    // We don't want to import JS strings as `String`, since Rust already has a
    // `String` type in its prelude, so rename it as `JsString`.
    #[wasm_bindgen(js_name = String)]
    type JsString;

    // This is a method on the JavaScript "String" class, so specify that with
    // the `js_class` attribute.
    #[wasm_bindgen(method, js_class = "String", js_name = charAt)]
    fn char_at(this: &JsString, index: u32) -> JsString;
}
#}