Function named_context_system 

pub fn named_context_system<F>(
    name: &'static str,
    function: F,
) -> SystemSpec<ContextSystem<F>>
where
    F: for<'w, 'e, 'c> FnMut(&mut SystemContext<'w, 'e, 'c>),

Wrap a context-aware closure together with its registration name.