syntax_data: {"ast_node_type":"other","tokens":[{"end":99,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:         // our current location after every insertion. By iterating backwards, we dodge this issue:
context_before:         // statements/blocks after. Iterating or visiting the MIR in order would require updating
context_after:         // The only Locations that an insertion changes have already been handled.