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: symbol_env.rs
    path of file: ./repos/wing/libs/wingc/src/type_check
    
    the code of the file until where you have to start completion: use colored::Colorize;
use derivative::Derivative;
use duplicate::duplicate_item;

use crate::{
	ast::{AccessModifier, Phase, Symbol},
	diagnostic::{DiagnosticAnnotation, TypeError, WingSpan},
	type_check::{SymbolKind, Type, TypeRef},
};
use std::fmt::Debug;
use std::{
	collections::{btree_map, BTreeMap, HashSet},
	fmt::Display,
};

use super::{UnsafeRef, VariableInfo};

pub type SymbolEnvRef = UnsafeRef<SymbolEnv>;

impl Debug for SymbolEnvRef {
	fn fmt(&self, f: &mut std::fmt::
    
	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
		let mut level = 0;
		let mut env = self;
		loop {
			write!(f, "level {}: {{ ", level.to_string().bold())?;
			let mut items = vec![];
			for (name, entry) in &env.symbol_map {
				let repr = match &entry.kind {
					SymbolKind::Type(t) => format!("{} [type]", t).red(),
					SymbolKind::Variable(v) => format!("{}", v.type_).blue(),
					SymbolKind::Namespace(ns) => format!("{} [namespace]", ns.name).green(),
				};
				items.push(format!("{} => {}", name.bold(), repr));
			}
			write!(f, "{} }}", items.join(", "))?;

			if let Some(parent) = &env.parent {
				env = parent;
				level += 1;
				writeln!(f)?; // new line
			} else {
				break;
			}
		}

		Ok(())
	}