syntax_data: {"ast_node_type":"other","tokens":[{"end":51,"kind":"keyword","start":0,"text":"Unevaluated(uv)"}]}
source_snippet:             Unevaluated(uv) => write!(f, "{uv:?}"),
context_before:             Placeholder(placeholder) => write!(f, "{placeholder:?}"),
context_after:             Value(val) => write!(f, "{val:?}"),