syntax_data: {"ast_node_type":"other","tokens":[{"end":79,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// fields (that would be similar to hashing pointers, since those are just
context_before:     /// Hashes a span in a stable way. We can't directly hash the span's `BytePos`
context_after:     /// offsets into the `SourceMap`). Instead, we hash the (file name, line, column)