Convert a HeaderValue into a rust String

HeaderValueExt.rs

/// Additional conversion methods for `HeaderValue`.
pub trait HeaderValueExt {
  fn to_string(&self) -> String;
}

impl HeaderValueExt for HeaderValue {
  fn to_string(&self) -> String {
    self.to_str().unwrap_or_default().to_string()
  }
}

// Usage:
let ok: Option<String> = request.headers().get("ok").map(|x| x.to_string());