syntax_data: {"ast_node_type":"other","tokens":[{"end":66,"kind":"keyword","start":0,"text":"if"}]}
source_snippet:                             if !src_ref.is_mut && dst_ref.is_mut {
context_before:                         |(dst_ref, dst_state_prime)| {
context_after:                                 Answer::No(Reason::DstIsMoreUnique)