syntax_data: {"ast_node_type":"other","tokens":[{"end":72,"kind":"keyword","start":0,"text":"self.check_let_chain(chain_refutabilities,"}]}
source_snippet:                     self.check_let_chain(chain_refutabilities, ex.span);
context_before:                 if chain_refutabilities.iter().any(|x| x.is_some()) {
context_after:                 }