syntax_data: {"ast_node_type":"import","tokens":[{"end":93,"kind":"keyword","start":0,"text":"#[rustc_lint_opt_deny_field_access(\"use"}]}
source_snippet:     #[rustc_lint_opt_deny_field_access("use `Session::mir_opt_level` instead of this field")]
context_before:          details about types, etc. (boolean for all passes, 'nll' to enable in NLL MIR only, default: 'nll')"),
context_after:     mir_opt_level: Option<usize> = (None, parse_opt_number, [TRACKED],