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: cache.rs
    path of file: ./repos/deno/cli/lsp
    
    the code of the file until where you have to start completion: // Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.

use crate::cache::HttpCache;
use crate::util::path::specifier_to_file_path;

use deno_core::parking_lot::Mutex;
use deno_core::ModuleSpecifier;
use std::collections::HashMap;
use std::fs;
use std::path::Path;
use std::sync::Arc;
u
    
pub fn calculate_fs_version_at_path(path: &Path) -> Option<String> {
  let metadata = fs::metadata(path).ok()?;
  if let Ok(modified) = metadata.modified() {
    if let Ok(n) = modified.duration_since(SystemTime::UNIX_EPOCH) {
      Some(n.as_millis().to_string())
    } else {
      Some("1".to_string())
    }
  } else {
    Some("1".to_string())
  }
}