syntax_data: {"ast_node_type":"other","tokens":[{"end":50,"kind":"keyword","start":0,"text":"self.check_binding_is_irrefutable("}]}
source_snippet:                 self.check_binding_is_irrefutable(
context_before:                 let [pat_field] = &subpatterns[..] else { bug!() };
context_after:                     &pat_field.pattern,