syntax_data: {"ast_node_type":"other","tokens":[{"end":72,"kind":"keyword","start":0,"text":"Span::new(self.lo(),"}]}
source_snippet:             Span::new(self.lo(), split_pos, self.ctxt(), self.parent()),
context_before:         (
context_after:             Span::new(split_pos, self.hi(), self.ctxt(), self.parent()),