syntax_data: {"ast_node_type":"other","tokens":[{"end":69,"kind":"keyword","start":0,"text":"(ty::ImplPolarity::Negative,"}]}
source_snippet:         (ty::ImplPolarity::Negative, ty::ImplPolarity::Positive) => {
context_before:     match (impl_polarity, other_polarity) {
context_after:             Err(report_negative_positive_conflict(