syntax_data: {"ast_node_type":"other","tokens":[{"end":36,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:                     // content hash.
context_before:                     // We can only use the heuristic because `add_external_src` checks the file
context_after:                     self.path_mapping.reverse_map_prefix_heuristically(virtual_name)?.into()