syntax_data: {"ast_node_type":"other","tokens":[{"end":23,"kind":"keyword","start":0,"text":"src.drain(..3);"}]}
source_snippet:         src.drain(..3);
context_before:     if src.starts_with('\u{feff}') {
context_after:         normalized_pos.push(NormalizedPos { pos: RelativeBytePos(0), diff: 3 });