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: lock.rs
    path of file: ./repos/phaser/phaser/vendor/futures-channel/src
    
    the code of the file until where you have to start completion: //! A "mutex" which only supports `try_lock`
//!
//! As a futures library the eventual call to an event loop should be the only
//! thing that ever blocks, so this is assis
    
    fn deref_mut(&mut self) -> &mut T {
        // The existence of `TryLock` represents that we own the lock, so we
        // can safely access the data here.
        //
        // Additionally, we're the *only* `TryLock` in existence so mutable
        // access should be ok.
        unsafe { &mut *self.__ptr.data.get() }
    }