syntax_data: {"ast_node_type":"other","tokens":[{"end":65,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// adding any drops onto the end of `block` that are needed.
context_before:     /// Pops a scope, which should have region scope `region_scope`,
context_after:     /// This must match 1-to-1 with `push_scope`.