syntax_data: {"ast_node_type":"other","tokens":[{"end":81,"kind":"keyword","start":0,"text":"//!"}]}
source_snippet: //! closure and return a new coroutine that will hold onto all of these captures,
context_before: //! by reference is now captured by value. This means that we consume the outer
context_after: //! and drop them when it is finished (i.e. after it has been `.await`ed).