syntax_data: {"ast_node_type":"other","tokens":[{"end":78,"kind":"keyword","start":0,"text":"ProcMacroSourceCode(_)"}]}
source_snippet:             ProcMacroSourceCode(_) => write!(fmt, "<proc-macro source code>"),
context_before:             Anon(_) => write!(fmt, "<anon>"),
context_after:             CliCrateAttr(_) => write!(fmt, "<crate attribute>"),