{"ast_node_type":"import","tokens":[{"end":86,"kind":"keyword","start":0,"text":"///"}]}
/// // 42 implements the tracing::Value trait, otherwise use one of the options below)
/// // logs a span named "hello" with a field named "arg" of value 42 (works only because
/// let _span = enter_trace_span!(M, "hello", arg = 42);