syntax_data: {"ast_node_type":"other","tokens":[{"end":74,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// Map for finding the index of an existing node, given its contents.
context_before:     drop_nodes: IndexVec<DropIdx, DropNode>,
context_after:     existing_drops_map: FxHashMap<DropNodeKey, DropIdx>,