syntax_data: {"ast_node_type":"other","tokens":[{"end":37,"kind":"keyword","start":0,"text":"if"}]}
source_snippet:         if a.polarity != b.polarity {
context_before:         let trait_ref = relation.relate(a.trait_ref, b.trait_ref)?;
context_after:             return Err(TypeError::PolarityMismatch(ExpectedFound::new(a.polarity, b.polarity)));