syntax_data: {"ast_node_type":"other","tokens":[{"end":75,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// isize`) would then be assigned a De Bruijn index of 1, meaning "the
context_before:     /// fn). The region `'a` that appears in the second argument type (`&'a
context_after:     /// second-innermost binder". (These indices are written on the arrows