syntax_data: {"ast_node_type":"other","tokens":[{"end":100,"kind":"keyword","start":0,"text":"UnsafeBlock"}]}
source_snippet:     UnsafeBlock { span: Span, hir_id: HirId, used: bool, nested_used_blocks: Vec<NestedUsedBlock> },
context_before:     UnsafeFn,
context_after: }