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: class_fields_use_set.rs
    path of file: ./repos/swc/crates/swc_ecma_transforms_compat/src
    
    the code of the file until where you have to start completion: use std::mem;

use swc_common::{util::take::Take, DUMMY_SP};
use swc_ecma_ast::*;
use swc_ecma_utils::{
    constructor::inject_after_super, default_constructor, is_literal, is_simple_pure_expr,
    private_ident, prop_name_to_member_prop, ExprFactory, ModuleItemLike, StmtLike,
};
use swc_ecma_visit::{as_folder, noop_visit_mut_type
    
    fn visit_mut_class(&mut self, n: &mut Class) {
        n.visit_mut_children_with(self);

        let mut fields_handler = FieldsHandler::default();
        n.visit_mut_with(&mut fields_handler);

        let FieldsHandler {
            constructor_inits,
            constructor_found,
            ..
        } = fields_handler;

        if constructor_inits.is_empty() {
            return;
        }

        let mut constructor_handler = ConstructorHandler {
            has_super: n.super_class.is_some(),
            constructor_inits,
            constructor_found,
        };
        n.visit_mut_with(&mut constructor_handler);
    }