রাস্ট contains_key

fn main() {
  use std::collections::HashMap;

  let mut user = HashMap::new();
  user.insert("নাম", "মোঃ আরিফ");
  user.insert("দেশ", "বাংলাদেশ");

  let result = user.contains_key("নাম");

  println!("{}", result);
}