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: lib.rs
    path of file: ./repos/book/listings/ch15-smart-pointers/listing-15-22/src
    
    the code of the file until where you have to start completion: pub trait Messenger {
    fn send(&self, msg: &str);
}

pub struct LimitTracker<'a, T: Messenger> {
    messenger: &'a T,
    value: usize,
    max: usize,
}

impl<'a, T> LimitTracker<'a, T>
where
    T: Messenger,
{
    pub fn
    
    fn it_sends_an_over_75_percent_warning_message() {
        // --snip--
        // ANCHOR_END: here
        let mock_messenger = MockMessenger::new();
        let mut limit_tracker = LimitTracker::new(&mock_messenger, 100);

        limit_tracker.set_value(80);
        // ANCHOR: here

        // ANCHOR: here
        assert_eq!(mock_messenger.sent_messages.borrow().len(), 1);
    }