syntax_data: {"ast_node_type":"other","tokens":[{"end":78,"kind":"keyword","start":0,"text":"visitor.check_binding_is_irrefutable(pattern,"}]}
source_snippet:             visitor.check_binding_is_irrefutable(pattern, origin, None, None);
context_before:         if let Some(box ref pattern) = param.pat {
context_after:         }