syntax_data: {"ast_node_type":"variable","tokens":[{"end":39,"kind":"keyword","start":0,"text":"if"}]}
source_snippet:     if let Some(x) = x.checked_sub(1) {
context_before: pub(crate) fn push_integer_62(x: u64, output: &mut String) {
context_after:         output.push_str(&x.to_base(62));