syntax_data: {"ast_node_type":"other","tokens":[{"end":93,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:     // one past the end of a file to belong to it. Normally, that's what we want. But for the
context_before:     // `SourceMap::lookup_source_file_idx` and `SourceFile::contains` both consider the position
context_after:     // purposes of converting a byte position to a line and column number, we can't come up with a