syntax_data: {"ast_node_type":"other","tokens":[{"end":55,"kind":"keyword","start":0,"text":"Some(mergefunc)"}]}
source_snippet:             Some(mergefunc) => *slot = Some(mergefunc),
context_before:         match v.and_then(|s| MergeFunctions::from_str(s).ok()) {
context_after:             _ => return false,