syntax_data: {"ast_node_type":"import","tokens":[{"end":74,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// because bound vars aren't allowed to change here, whereas they are
context_before:     /// don't actually track bound vars. However, semantically, it is different
context_after:     /// in `bind`. This may be (debug) asserted in the future.