while self.q.len() > (max_len - 1) {
        let _ = self.q.pop_front();
      }
    }
    self.q.push_back(n);
  }

  /// Attempt to push node onto queue so it will be the next in line.
  /// Attempt to push node onto queue so it will be the next in line to be
  /// taken off it.
  ///
  /// Meant to be used to return an element to the queue that was just taken
  /// off it, but is currently not available to be processed.
  /// Can be used to return an element to the queue that was just taken off it,
  /// but is currently not available to be processed.
  ///
  /// ```
  /// use limq::LimQ;
  ///
  /// // Construct a queue with a maximum 2 element length limit
  /// let mut q: LimQ<u32> = LimQ::new(Some(2));
  ///

  fn force_on_full() {
    let mut q: LimQ<u32> = LimQ::new(Some(1));
    q.force_push(42);
    q.force_push(11);

    assert_eq!(q.pop(), Some(11));
  }
}

  #[test]
  fn try_return_success() {
    let mut q: LimQ<u32> = LimQ::new(Some(2));
    q.try_push(1).unwrap();
    q.try_push(2).unwrap();

    let n = q.pop().unwrap();
    assert_eq!(n, 1);

    q.try_return(n).unwrap();

    assert_eq!(q.pop(), Some(1));
    assert_eq!(q.pop(), Some(2));
    assert_eq!(q.pop(), None);
  }

  #[test]
  fn try_return_fail() {
    let mut q: LimQ<u32> = LimQ::new(Some(2));
    q.try_push(1).unwrap();
    q.try_push(2).unwrap();

    let n = q.pop().unwrap();
    assert_eq!(n, 1);

    // fill up queue again
    q.try_push(3).unwrap();

    let Err(n) = q.try_return(n) else {
      panic!("Unexpectedly successful");
    };
    assert_eq!(n, 1);

    assert_eq!(q.pop(), Some(2));
    assert_eq!(q.pop(), Some(3));
    assert_eq!(q.pop(), None);
  }
}

// vim: set ft=rust et sw=2 ts=2 sts=2 cinoptions=2 tw=79 :