syntax_data: {"ast_node_type":"function","tokens":[{"end":43,"kind":"keyword","start":0,"text":"fn"}]}
source_snippet:     fn push_integer_62(&mut self, x: u64) {
context_before:     ///   e.g. `1` becomes `"0_"`, `62` becomes `"Z_"`, etc.
context_after:         push_integer_62(x, &mut self.out)