syntax_data: {"ast_node_type":"other","tokens":[{"end":98,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:         // the callsite span and the span will be pointing at different places. It also means that
context_before:         // FIXME: If this span comes from a `derive` macro but it points at code the user wrote,
context_after:         // we can safely provide suggestions on this span.