syntax_data: {"ast_node_type":"function","tokens":[{"end":69,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// fn type it is bound by, the inner or the outer one. There are
context_before:     /// fn). We need to be able to determine, for any given region, which
context_after:     /// various ways you can do this, but a De Bruijn index is one of the